# Undergravel filters are not bad



## RCinAL

I recently joined this forum and was somewhat surprised by the number of hobbyist who dislike undergravel filters. I have had a conventional one in every tank since the 1970's, and since this adds up to dozens of undergravel filters over several decades, I thought I might be qualified to clear up a few concerns. I only went to reverse flow a week ago, (Thanks for the advice, Bryan!), but can already explain some amazing benefits of this set-up too. This is my opinion based on many years of experience and I am entitled to it. If you feel otherwise, don't flame me. Instead, post a response expounding your own experiences and let the readers decide for themselves. 

From what I can tell, the most common undergravel concerns are: 1) They are "old technology" and have out-lived their usefulness in the hobby. 2) They offer poor filtration. 3) They are not suited for growing live plants. 4) "Muck" collects underneath them and is impossible to remove. 5) They clog up constantly, fouling the tank and creating maintenance woes or killing the bio-mass of beneficial bacteria. 6) They are hard to clean. 

In the same order, here are my responses:

1) They are old technology for sure, but this alone is a ridiculous reason to avoid them. The latest, most expensive and complicated solutions are not always the best answer to life's simple problems.

2) They do offer very poor mechanical and chemical filtration, but when properly maintained the biological benefits are huge. And remember, biological filtration is the most important and the one you can never have too much of. In conjunction with a good power filter, they do offer worthwhile benefits.

3) I am not a horticulturist, neither in gardens, pots, nor aquariums, so I wouldn't argue with this except to say that not everyone cares about it. That most all tropical fish will thrive in unplanted tanks with 3 different types of filtration (biological, mechanical, and chemical) along with regular partial water changes is an established fact. I prefer the look and convenience of artificial plants, and undergravel filters are fine for this. I also enjoy replacing my expensive bulbs only when they refuse to light up - about every 5 years and sometimes much longer.

4) Totally agree, but not a problem with pre-filtered, reverse-flow powerheads.

5) Not if kept clean. And again, not much of a problem at all with pre-filtered, reverse-flow powerheads. These push only filtered water through your undergravel filter solely for the benefit of biological filtration and do nothing to clog the substrate. Indeed, the reverse flow option may even keep gravel cleaner than using nothing because it discourages floating debris in the tank from settling in it. 

6) Hogwash. Until last week I had used a conventional undergravel filter in every tank I have owned (about 25 total) for well over 30 years, and sometimes nothing else. And as long as I did not over-feed the fish, the gravel only needed cleaning about once a month and could be stretched to twice that in under-populated tanks. This is done during bi-weekly water changes and adds no extra time to this simple responsibility. All you need is a bucket and a simple, inexpensive gravel siphon. Coincidently, the siphon tool actually makes scheduled water changes much easier and is probably something you will want to own anyway.

I have a theory that undergravel filters earned their poor reputation in the past, and mainly for symptoms relative to a fault which I have never even heard discussed: *Conventional ones did encourage over-feeding*, especially if there were bottom feeders in the tank. Any food that was targeted at bottom feeders was quickly sucked into the gravel and out of reach of the hungry fish where it fouled the filter media (gravel) prematurely and caused maintenance headaches. The lowest fish starved though plenty of food hit the bottom only to disappear into the gravel. I learned quickly it was better not to keep bottom feeders than to foul my undergravel filters trying to get enough food to them. For this reason I have had a decades-long happy affair with even conventional undergravel filters, though I am certain most aquarists continued to over-feed and hated them. Again, the advent of reverse-flow has totally eliminated even this problem for attentive aquarists.

Though I have done it many times and for years at a stretch, I do not recommend using undergravel filters as the sole means of filtration. Canisters and power filters are just too inexpensive and good these days to not have one on every tank - at least for primary mechanical and chemical filtration. (I prefer hang on the tank power filters for their unmatched ease of cartridge maintenance and lack of hoses and connectors.) However, unless you want live plants rooted in fine, fertile substrate, adding a reverse-flow undergravel filter to an already good freshwater system does make it better.

Look at it this way - You already have gravel in the bottom of your tank and it should be cleaned occasionally anyway. Why would you choose not to circulate a supply of clean, oxygenated water through it for the benefit of critical biological filtration? This is probably the largest surface area in the tank. It seems a shame not to use it as anything more than decoration.

Sponge filters seem to be all the rave these days and enjoy much praise for their superior biological qualities. But they are UGLY, and take up _waaay_ too much room in the tank, at least in my opinion. And they must be regularly removed from the tank and replaced, or at least rinsed and squeezed out in a sink, totally disrupting the bio-mass. Not so with an easier-on-the-eyes undergravel filter. It remains inside the tank forever - even during cleanings - with it's bacteria mostly in tact, so there is much less chance of harmful toxins ever spiking and killing your prized fish.

And one more thing concerning undergravel filters used in conjunction with power filters for extra biological filtration - they can be run with a cheap, battery operated air pump during power failures. This has saved my fish more than once. During an interruption, power filters stop and their bacteria quickly die off, but undergravels can be kept in emergency service rather cheaply.

Listen, aquariums need all the biological filtration they can get. You can't go wrong by adding a simple, effective, undergravel filter to your fish's life support system. And they do have their benefits over other types of filters. The more I research other methods, the better I like my undergravel filters.

Hope this helps somebody.

Ralph


----------



## tanker

My little 3-gallon plastic tank came with an undergravel filter. I successfully kept a couple of guppies in there for ages (before I knew that guppies should be in a bigger tank), until a tube thing broke and I couldn't find a replacement. That's something I would NOT want to do on a big tank - remove or replace an undergravel filter. 

When I moved my fish into a bigger tank, I rinsed all but a cup of gravel. There was muck in the gravel even after weekly water changes and gravel siphoning. I think there is a certain amount of muck that'll drop to the bottom of the tank regardless of your filtration system. 

I thought the issue with the plants was that the roots could clog up the slits in the filter. I can imagine that a plant with a fibrous root system could plug things up pretty quickly (but that's just going by what I know of terrestrial plants, I'm a novice when it comes to my aquarium plants.)

I like your point about having the oxygen circulating through the gravel. My tanks are all set up now so I won't be getting an undergravel filter in mine, but you've certainly made me reconsider their value. Interesting.


----------



## Mikaila31

Nothing wrong with reverse flow UGF IMO, most of what you say is correct, but.....

All you need on any tank at the MOST is biological and mechanical filtration, the properly setup tank can void both of these things. Chemical filtration is never necessary. The vast majority prefer live plants since they come with many benefits. If you are using T8 bulbs these are cheap to replace unless you fall to marketing, only expensive bulbs in this hobby are power compacts, T5's, metal halides, LEDs, ect. 

You hit my big beef with UGF "it stays in the tank forever" I am much happier to stick with my ugly sponge filter that takes up to much room. It goes in and out in minuets. Also I can build a sponge filter with mostly garbage+ a powerhead. If you think those fancy fluvals are ugly then you haven't seen the things I filter with :lol:. Trust me I don't pick a filter over looks most the time. However cleaning a sponge does not significantly harm the bacteria on it.

Unless you have really long power outages or unstable tanks this issue is not a factor. Even the crappiest HOB filter should last 6 hours during a power outage with insignificant bacterial loss. A internal or canister will last longer. Also sponge filters can be run on powerheads too. IMO bacteria in our filter lasts a lot longer then you give it credit for. Vast majority of power outages are less then 8 hours in which case for most filters you don't have to do anything. Canisters require some labor to run after 8 hours, at which time you should start moving water through it. Very easy to do, just disconnect the output and as soon as you lower the hose below the water level you have a siphon. Just pull new water into canister and pour the stuff that comes out back into the tank. Do this for ten minuets or so ever 2 hours AFTER 8 hours have gone by.

Lastly I can just do away with the silly idea of a filter and just set my tanks up properly;-). Two of my tanks operate without any filter. One can go at least a week sitting stagnant(I intentionally left the filter off to see and one week of the tank being stagnant, nothing exciting happened:-?) This same tank is not filtered at least 6 hours of the day, since its noisy I turn it off when I go to sleep. I've never tested the big tank, would depend on alot of factors. It could go at least 24 hours stagnant. It holds all my breeding groups, so it always gets the most attention anyway. 

I prefer plants, and when I don't have the option of having plants I might as well not have gravel. The issue with UGF and plants is if you want plants you actually want crap to build up in the gravel. Frequent cleaning it is the last thing you want to do. If you run a UFG in the original manner and over feed it would probably work. But a reverse flow wouldn't work as well for plants.

The benefits of every filter depends on the type of tank you want to run. You can not come straight out and say one filter has more benefits then the other. It doesn't work that way. Its like trying to say a minivan is better then a sportcar. To some it might be to others it might not. Depends what you want your filter to do.


----------



## ginagv

*tell me more please*

4) Totally agree, but not a problem with pre-filtered, reverse-flow powerheads.

Hi Ralph,

Tell me more about these reverse flow powerheads please? I have an undergravel filter in my 20 gal tall, and I have an outside filter as well.. I will continue to use both, but I am interested in what you mean by pre-filtered reverse flow powerheads..

thanks,

Gina


----------



## RCinAL

ginagv said:


> 4) Totally agree, but not a problem with pre-filtered, reverse-flow powerheads.
> 
> Hi Ralph,
> 
> Tell me more about these reverse flow powerheads please? I have an undergravel filter in my 20 gal tall, and I have an outside filter as well.. I will continue to use both, but I am interested in what you mean by pre-filtered reverse flow powerheads..
> 
> thanks,
> 
> Gina


Gina,

Google "Penguin 660R powerhead". It is just a standard powerhead that comes with a kit that lets you send the discharge *down* the undergravel filter's tubes instead of pulling water up them. This completely changes how your undergravel works for the better. It comes with a small filter kit that goes over the intake to clean the water before it is sent down. Here is a link to the owner's manual: http://www.marineland.com/sites/Marineland/Documents/psponge_manual.pdf There is a good clear photo at the top of page 8 that shows a prefiltered reverse flow set-up.

There are other brands. This just happens to be the particular one I have. You can also buy just the reverse-flow "kit" if you already have a compatable powerhead.


----------



## RCinAL

Mikaila31 said:


> Nothing wrong with reverse flow UGF IMO, most of what you say is correct, but.....
> 
> All you need on any tank at the MOST is biological and mechanical filtration, the properly setup tank can void both of these things. Chemical filtration is never necessary. The vast majority prefer live plants since they come with many benefits. If you are using T8 bulbs these are cheap to replace unless you fall to marketing, only expensive bulbs in this hobby are power compacts, T5's, metal halides, LEDs, ect.
> 
> You hit my big beef with UGF "it stays in the tank forever" I am much happier to stick with my ugly sponge filter that takes up to much room. It goes in and out in minuets. Also I can build a sponge filter with mostly garbage+ a powerhead. If you think those fancy fluvals are ugly then you haven't seen the things I filter with :lol:. Trust me I don't pick a filter over looks most the time. However cleaning a sponge does not significantly harm the bacteria on it.
> 
> Unless you have really long power outages or unstable tanks this issue is not a factor. Even the crappiest HOB filter should last 6 hours during a power outage with insignificant bacterial loss. A internal or canister will last longer. Also sponge filters can be run on powerheads too. IMO bacteria in our filter lasts a lot longer then you give it credit for. Vast majority of power outages are less then 8 hours in which case for most filters you don't have to do anything. Canisters require some labor to run after 8 hours, at which time you should start moving water through it. Very easy to do, just disconnect the output and as soon as you lower the hose below the water level you have a siphon. Just pull new water into canister and pour the stuff that comes out back into the tank. Do this for ten minuets or so ever 2 hours AFTER 8 hours have gone by.
> 
> Lastly I can just do away with the silly idea of a filter and just set my tanks up properly;-). Two of my tanks operate without any filter. One can go at least a week sitting stagnant(I intentionally left the filter off to see and one week of the tank being stagnant, nothing exciting happened:-?) This same tank is not filtered at least 6 hours of the day, since its noisy I turn it off when I go to sleep. I've never tested the big tank, would depend on alot of factors. It could go at least 24 hours stagnant. It holds all my breeding groups, so it always gets the most attention anyway.
> 
> I prefer plants, and when I don't have the option of having plants I might as well not have gravel. The issue with UGF and plants is if you want plants you actually want crap to build up in the gravel. Frequent cleaning it is the last thing you want to do. If you run a UFG in the original manner and over feed it would probably work. But a reverse flow wouldn't work as well for plants.
> 
> The benefits of every filter depends on the type of tank you want to run. You can not come straight out and say one filter has more benefits then the other. It doesn't work that way. Its like trying to say a minivan is better then a sportcar. To some it might be to others it might not. Depends what you want your filter to do.


You sound like an experienced, dedicated hobbyist and make some very good points. I wouldn't disagree with you on any of them except to say we are all different with different motivations and goals. That is one thing that makes the hobby great! 

Though I have had as many as 8 at a time, (I used to pay for my fish habit by raising and selling Africans to retailers), I now only keep one community "show" tank and I want lots of fish and plenty of "action". I plan to over-stock it a bit and therefore think I could use the extra biological benefits of the set-up I described. And since it is a show tank, I don't want a sponge filter in it. That's just me. But I admit I am not crazy about all the extra hardware in the tank to go reverse-flow either. Trade-offs, trade-offs.

I had never been part of an aquarium "community" like this forum and had no idea undergravel filters had become so controversial till reading comments here. Being an advocate of them, I felt the need to toot my horn a bit on the subject and let others know they do have some benefits and are still a viable option.

I have survived power outages of 2 days, 3 days, and 1 week. :shock: 12 hours is common around here. It gets old.

"Forever" is a relative term at my house. It means till the next move or Wifey's next furniture re-arrangement party. :lol: About 6 years tops. I should have clarified that.

Cheers!

Ralph


----------



## Pasfur

I think this is a great article. I myself have been in the freshwater hobby for about 30 years now. I would take the conversation a step further and suggest that Undergravel Filters and Sponge Filters are virtually identical in their benefits. 

At one time my fishroom had 34 freshwater aquariums, ranging in size from 2 gallons to 90 gallons, and every one of these was run by a sponge filter as the only source of biological filtration. The large majority did not have any other form of filtration. The key to keeping them from getting clogged and needing cleaning is very simple. You place the sponge filter under the gravel. Doing so allows you go to 6 months to a year between rinsing of the sponge. 

The sponge has the same additional advantages to a u/g filter. First, they can be operated by a battery operated air pump. Second, they can be used in conjunction with a reverse flow powerhead, preventing clogging. And finally, you can easily move the sponge from one aquarium to another, eliminating valuable cycling time when needing an emergency filter in a hospital or quarantine tank.

I post here as support to the original article on undergravel filters. The biological benefits are very valuable. I personally stopped using undergravel filters and sponge filters when the Penguin Biowheel units hit the market. Dollar for dollar they are less expensive to purchase and easier to service, and provide outstanding biological benefits. However, the advancement of one technology does not reduce the effectiveness of another.


----------



## VTonic

Pasfur said:


> I think this is a great article. I myself have been in the freshwater hobby for about 30 years now. I would take the conversation a step further and suggest that Undergravel Filters and Sponge Filters are virtually identical in their benefits.
> 
> At one time my fishroom had 34 freshwater aquariums, ranging in size from 2 gallons to 90 gallons, and every one of these was run by a sponge filter as the only source of biological filtration. The large majority did not have any other form of filtration. The key to keeping them from getting clogged and needing cleaning is very simple. You place the sponge filter under the gravel. Doing so allows you go to 6 months to a year between rinsing of the sponge.
> 
> The sponge has the same additional advantages to a u/g filter. First, they can be operated by a battery operated air pump. Second, they can be used in conjunction with a reverse flow powerhead, preventing clogging. And finally, you can easily move the sponge from one aquarium to another, eliminating valuable cycling time when needing an emergency filter in a hospital or quarantine tank.
> 
> I post here as support to the original article on undergravel filters. The biological benefits are very valuable. I personally stopped using undergravel filters and sponge filters when the Penguin Biowheel units hit the market. Dollar for dollar they are less expensive to purchase and easier to service, and provide outstanding biological benefits. However, the advancement of one technology does not reduce the effectiveness of another.


I 100% agree. I have used undergravel filters for 10 years on and off depending on the aquarium. Currently in my display tank I dont use one but in my 10 gallon office tank and my hospital tank I most deffinetly use them. An under gravel filter used in conjunction with a HOB filter (my 10gal is currently using the penguin bio-wheel 100) will work superbly. As I said I am currently using both in one system and I have to say that my bio,mech,chem filtration is incredible. When using a HOB filter with it, it almost makes maintaining the undergravel filter unnecessary and you get the added benefits of increased bio filtration. However, I will say that in this day and age when you have a sea of filtration options I would never use one as my sole form of filtration. Filters are just to cheap to not have something else running in conjunction with it. All of this is depended on you not over feeding of course. Just my opinion.


----------



## redchigh

Well, undergravel filters remove a bit more suspended matter than UG's... This is only from reading, as I've never ran either one.


Before I decided plants, I was close to setting up an UG filter. If I set up a marine tank, I'll probably use one. 

The only problem with UG filters and plants is that the UG filter prevents rooted plants from bringing in nutrients. Root tabs and enriched substrates would only cause a huge mess.

UG's are great for african lakes where you never want to use a plant, but I would imagine you can't just stop using the filter when you want. Wouldn't the bacteria in the substrate hurt the water?
*shrug*


----------



## Pasfur

redchigh said:


> Well, undergravel filters remove a bit more suspended matter than UG's... This is only from reading, as I've never ran either one.


There is confusion or a typo here. Undergravel filters and UG's are the same thing. Its just an abbreviation.


----------



## Cpt NAPA

I started in tropical fish in 1964 and went to work in a lfs in Campbell California. It was one of the largest tropical fish stores in California at the time and we had fresh and saltwater tanks. We imported marine fish from Oakinawa,The Phillapines and Singapore. Every tank in the store with the exception of the quarintine tanks in the back had undergravel filters. 
As my interest and particapation in the hobby blossomed I increased my tanks at home to 30 and bred and raised many fish to sell to the store I worked in and other stores in the area. I ran a 130 tank hatchery for a friend for several years from '65 to '67 raising corys, Kissers, danios and angels to name a few. I used Metaframe Hatchery flats for grow out tanks and breeding tanks for the cors. Yep they all had underegravel filters. 
The tanks all got regular water changes and at the end of a grow out cycle they were torn down and the gravel rinsed out before the next brood was placed in for growing to saleable size but they did a great job. In the hatchery flats I would grow angels to saleable size in 8 weeks and put approx 30 water sprite plantlets in the tank with flourescent lights over them and have some great looking sprite to sell when the angels were ready to market. Oh what fun.
I was out of the hobby for the last 10 or 15 years and just last spring I got my hands on a 30g long tank and set it up in my dining room. Got it at a yard sale so it came with a HOB power filter. I ordered a undergravel filter from a lfs because they don't stock them anymore. It is up and running with Water sprite, Cryptocorne wendtii, Hygrophila corymbosa 'siamensis'. I am using the HOB that came with the tank but I wouldn't want to do it W/O my trusty UG. 

I realize that the majority of the hobbists use power HOB or canister filters exclusively nowadays but as was stated earlier in this thread, old school isn't always bad or even worse than the new stuff.
Glad to have someware to join in. Cpt Napa 
PS now where the heck is that spell checker


----------



## catdawg426

Cpt NAPA said:


> I started in tropical fish in 1964 and went to work in a lfs in Campbell California. It was one of the largest tropical fish stores in California at the time and we had fresh and saltwater tanks. We imported marine fish from Oakinawa,The Phillapines and Singapore. Every tank in the store with the exception of the quarintine tanks in the back had undergravel filters.
> As my interest and particapation in the hobby blossomed I increased my tanks at home to 30 and bred and raised many fish to sell to the store I worked in and other stores in the area. I ran a 130 tank hatchery for a friend for several years from '65 to '67 raising corys, Kissers, danios and angels to name a few. I used Metaframe Hatchery flats for grow out tanks and breeding tanks for the cors. Yep they all had underegravel filters.
> The tanks all got regular water changes and at the end of a grow out cycle they were torn down and the gravel rinsed out before the next brood was placed in for growing to saleable size but they did a great job. In the hatchery flats I would grow angels to saleable size in 8 weeks and put approx 30 water sprite plantlets in the tank with flourescent lights over them and have some great looking sprite to sell when the angels were ready to market. Oh what fun.
> I was out of the hobby for the last 10 or 15 years and just last spring I got my hands on a 30g long tank and set it up in my dining room. Got it at a yard sale so it came with a HOB power filter. I ordered a undergravel filter from a lfs because they don't stock them anymore. It is up and running with Water sprite, Cryptocorne wendtii, Hygrophila corymbosa 'siamensis'. I am using the HOB that came with the tank but I wouldn't want to do it W/O my trusty UG.
> 
> I realize that the majority of the hobbists use power HOB or canister filters exclusively nowadays but as was stated earlier in this thread, old school isn't always bad or even worse than the new stuff.
> Glad to have someware to join in. Cpt Napa
> PS now where the heck is that spell checker


You're right, they are really not as bad as people make them sound. I'm taking an aquatic biology class at my school and we have a little 10 gallon with a UG filter and it does great.


----------



## RCinAL

catdawg426 said:


> You're right, they are really not as bad as people make them sound. I'm taking an aquatic biology class at my school and we have a little 10 gallon with a UG filter and it does great.


I forgot I posted this and just remembered to come back and check out the comments. :lol:

Glad to see other experienced aquarists expressing opinions for and against. In the end it is all about whatever choice works for the individual and keeps _their_ fish happy.

Cheers!

Ralph


----------



## fan4guppy

Cpt NAPA said:


> I started in tropical fish in 1964 and went to work in a lfs in Campbell California. It was one of the largest tropical fish stores in California at the time and we had fresh and saltwater tanks. We imported marine fish from Oakinawa,The Phillapines and Singapore. Every tank in the store with the exception of the quarintine tanks in the back had undergravel filters.
> As my interest and particapation in the hobby blossomed I increased my tanks at home to 30 and bred and raised many fish to sell to the store I worked in and other stores in the area. I ran a 130 tank hatchery for a friend for several years from '65 to '67 raising corys, Kissers, danios and angels to name a few. I used Metaframe Hatchery flats for grow out tanks and breeding tanks for the cors. Yep they all had underegravel filters.
> The tanks all got regular water changes and at the end of a grow out cycle they were torn down and the gravel rinsed out before the next brood was placed in for growing to saleable size but they did a great job. In the hatchery flats I would grow angels to saleable size in 8 weeks and put approx 30 water sprite plantlets in the tank with flourescent lights over them and have some great looking sprite to sell when the angels were ready to market. Oh what fun.
> I was out of the hobby for the last 10 or 15 years and just last spring I got my hands on a 30g long tank and set it up in my dining room. Got it at a yard sale so it came with a HOB power filter. I ordered a undergravel filter from a lfs because they don't stock them anymore. It is up and running with Water sprite, Cryptocorne wendtii, Hygrophila corymbosa 'siamensis'. I am using the HOB that came with the tank but I wouldn't want to do it W/O my trusty UG.
> 
> I realize that the majority of the hobbists use power HOB or canister filters exclusively nowadays but as was stated earlier in this thread, old school isn't always bad or even worse than the new stuff.
> Glad to have someware to join in. Cpt Napa
> PS now where the heck is that spell checker


Not all use the new HOB or Canister filters. Personally I do not use Under Gravel filters but that is because of issues with bacteria affecting the Caudal fin of Guppies. The build up of bacteria when a guppy goes to a gravel bed can affect or shred the Guppy Tail (speaking show stock here). There is even some books (by well known breeders) upon the subject.

However I choose to use Sponge filters or the old box filters for my breeding set ups for guppies with no substrate involved. 

However for the species that you were breeding in this regard I would state that undergravel filters are a good form of biological filtration and many forget about the old ways involved in keeping fish. I too am a former pet shop employee


----------



## Mikaila31

And that would be why guppies are loosing their status as "hardy" fish:lol:.


----------



## AbbeysDad

I too have used UGF's on and off since the 70's.

I think UGF's are great, but can quickly fail if not setup and serviced properly.

UGF's are a great biological filter but come up short on mechanical, not because they don't do mechanical, but because they do.*
First, the UGF needs 2-3" of medium sized gravel - if the gravel is too coarse, excess food to quickly easily gets pulled under. If the gravel/sand is too fine, water flow gets restricted.
*Like all filters, the (gravel) media requires periodic cleaning to remove debris. This involves a gravel filter used at water changes.
I think where UGF's can fall down and fail for many is that they don't clean the filter and the debris decays and it becomes a nitrate factory.

What I find interesting is the lengths to which some folks go in canister and sumps in order to achieve what they believe is better bio-filtration...when it has been here all along.

I haven't used reverse flow, but see how that can work...but also see it working no better than conventional UGF with regular cleaning.
I tend to challenge the power head theory that more water faster is better. On the other hand, I subscribe to the theory that less (water) is more if/when filtration is better. I think the process works just fine/better with moving highly oxygenated water slowly through the filter bed.


----------



## DKRST

Add me to the pro-UG list - at least in an non-planted tank. Had a commercial account I serviced in the 1980's with a cube 250 gallon. Pain in the butt to work in, but had 4 UG plates with 3' lift tubes (1/corner). Never had a water quality problem except when the bartenders would feed the Oscars pickled olives...

Only trick when servicing was to vacuum/siphon out the mulm under the plates each and every time! Also used a gravel cleaner.


----------



## 1077

AbbeysDad said:


> I too have used UGF's on and off since the 70's.
> 
> I think UGF's are great, but can quickly fail if not setup and serviced properly.
> 
> UGF's are a great biological filter but come up short on mechanical, not because they don't do mechanical, but because they do.*
> First, the UGF needs 2-3" of medium sized gravel - if the gravel is too coarse, excess food to quickly easily gets pulled under. If the gravel/sand is too fine, water flow gets restricted.
> *Like all filters, the (gravel) media requires periodic cleaning to remove debris. This involves a gravel filter used at water changes.
> I think where UGF's can fall down and fail for many is that they don't clean the filter and the debris decays and it becomes a nitrate factory.
> 
> What I find interesting is the lengths to which some folks go in canister and sumps in order to achieve what they believe is better bio-filtration...when it has been here all along.
> 
> I haven't used reverse flow, but see how that can work...but also see it working no better than conventional UGF with regular cleaning.
> I tend to challenge the power head theory that more water faster is better. On the other hand, I subscribe to the theory that less (water) is more if/when filtration is better. I think the process works just fine/better with moving highly oxygenated water slowly through the filter bed.


 
Don't know why you would not favor
(Challenge) powerhead's with reverse flow capabilities(Have you tried it?) In undergravel filtration,
with traditional UG filter,dirt and debrii is pulled down into and under the plate which requires the reg maint you speak of to remove the crud( Anaerobic condition's)) that finds it's way under the plate.
With powerheads capable of reverse flow,, the water is pulled from the aquarium from atop the lift tubes via the powerheads in reverse flow, and water is pushed down and up under and through the plate, and no crud can collect there depending on the GPH rating of powerhead's used.
Does require pre-filter over the intake /output of powerheads assuming you wish for the inner workings of powerhead's to stay cleaner,longer.
Also need canister or HOB filter to clean the water that is being pushed back up through the substrate and once again pushed back down and under the plate. This is /should be,oxygen rich water. 
Is very effective filtration for large fishes that produce a lot of waste both while eating,,and excretement. This waste is prevented from gathering on the substrate, down in substrate,/under filter plate, and water turnover is usually sufficient to keep particulates in the water coulmn for afore mentioned canister or HOB filter to clean.Just need to keep mechanical material in filter clean but otherwise,,no more difficult than other filter maint which should be cleaned regularly.


----------



## fan4guppy

Mikaila31 said:


> And that would be why guppies are loosing their status as "hardy" fish:lol:.


The wild form guppy adapts to many water conditions in the wild and the aquarium world. However for show ornamental stock biological filtration affects many long finned species. More harm is actually done to many species in the case of fish farms using antibiotics and chemicals that have affected many species and not just the guppy as these situations affect many species immunity. This is more of a cause of the guppy loosing the hardy status as a lot of ornamental fishes that are bred by commercial fish farms that use this practice are affected. NOT JUST THE GUPPY!


----------



## DKRST

fan4guppy said:


> The wild form guppy adapts to many water conditions in the wild and the aquarium world. However for show ornamental stock biological filtration affects many long finned species. More harm is actually done to many species in the case of fish farms using antibiotics and chemicals that have affected many species and not just the guppy as these situations affect many species immunity. This is more of a cause of the guppy loosing the hardy status as a lot of ornamental fishes that are bred by commercial fish farms that use this practice are affected. NOT JUST THE GUPPY!


Concur - Folks (and commercial fish breeding industry) concentrate on breeding for specific traits and neglect the issue of inbreeding depression and overall species hardiness - same issue with many dog breeds. The expression "hybrid vigor" comes to mind. Less "pure" strains of dogs, and fish (= the "mutts") are often hardier.


----------



## AbbeysDad

1077 said:


> Don't know why you would not favor
> (Challenge) powerhead's with reverse flow capabilities(Have you tried it?) In undergravel filtration,
> with traditional UG filter,dirt and debrii is pulled down into and under the plate which requires the reg maint you speak of to remove the crud( Anaerobic condition's)) that finds it's way under the plate.
> With powerheads capable of reverse flow,, the water is pulled from the aquarium from atop the lift tubes via the powerheads in reverse flow, and water is pushed down and up under and through the plate, and no crud can collect there depending on the GPH rating of powerhead's used.
> Does require pre-filter over the intake /output of powerheads assuming you wish for the inner workings of powerhead's to stay cleaner,longer.
> Also need canister or HOB filter to clean the water that is being pushed back up through the substrate and once again pushed back down and under the plate. This is /should be,oxygen rich water.
> Is very effective filtration for large fishes that produce a lot of waste both while eating,,and excretement. This waste is prevented from gathering on the substrate, down in substrate,/under filter plate, and water turnover is usually sufficient to keep particulates in the water coulmn for afore mentioned canister or HOB filter to clean.Just need to keep mechanical material in filter clean but otherwise,,no more difficult than other filter maint which should be cleaned regularly.


Just realized I never responded. The reverse flow concept isn't bad, but unless throttled way back, I think power heads, moving water in either direction is bad. The UGF works best when highly oxygenated water is moved slowly through the bed. Bubble up UGF's with relatively clean gravel always worked well for me, and if it ain't broke don't add power heads and/or change direction.
:smile:
BUT there is a real problem with UGF's the way I think many people use them. If the gravel is not cleaned with a gravel siphon or other method, they are a ticking time bomb of a decaying mess that will eventually plug and turn out badly.


----------



## Mikaila31

AbbeysDad said:


> BUT there is a real problem with UGF's the way I think many people use them. If the gravel is not cleaned with a gravel siphon or other method, they are a ticking time bomb of a decaying mess that will eventually plug and turn out badly.


Thats exactly what the reverse flow fixes..... Pre filtered water is pumped under the grate and OUT through the gravel. The original method sucks debris INTO the gravel causing a eventual build up if not maintained properly. The whole point of reverse flow is to avoid debris from getting into the gravel, thus keeping the tank cleaner.


----------



## 1077

Mikaila31 said:


> Thats exactly what the reverse flow fixes..... Pre filtered water is pumped under the grate and OUT through the gravel. The original method sucks debris INTO the gravel causing a eventual build up if not maintained properly. The whole point of reverse flow is to avoid debris from getting into the gravel, thus keeping the tank cleaner.


+one, I give up!


----------



## Mr Fishy

redchigh said:


> Well, undergravel filters remove a bit more suspended matter than UG's... This is only from reading, as I've never ran either one.
> 
> 
> Before I decided plants, I was close to setting up an UG filter. If I set up a marine tank, I'll probably use one.
> 
> The only problem with UG filters and plants is that the UG filter prevents rooted plants from bringing in nutrients. Root tabs and enriched substrates would only cause a huge mess.
> 
> UG's are great for african lakes where you never want to use a plant, but I would imagine you can't just stop using the filter when you want. Wouldn't the bacteria in the substrate hurt the water?
> *shrug*


I have to disagree here. The 180 planted that I used to run had a full UG in it and the plants did better than any other setup I've ever run. I was trimming and selling plants every 3 days in that monster. Yes I had incredible lighting and C02 but the UG seemed to bring nutrients to the roots of the plants. The UG was the ONLY filter in the system too, no agitation of crazy currents to contend with either.


----------



## Mikaila31

I also don't quite buy the whole "UGF is bad for plants" thing. I've seen it done without a problem. If you actually thing about hydroponics its like the exact same thing. Lettuce for example is floated on a little raft with its roots in moving water. They do great like this. Fertilize the water column not the substrate, problem solved...


----------



## pharlley

we have had tanks for ever, and every time i get one, i am told by my father, to get the UGF....in the current 10g i have the platform, and had plants in it. seemed to grow great, until the last fish died and i transplanted.... i dont use the UGF anymore because its just too hard to find the replacement parts forthe brand (filter system is from 10 yrs ago plus, and pieces were lost in moves)


----------



## esmiller

*under-gravel filtration comments*

I too have used under- gravel filters for the better part of 40 years supplemented by hang-on-the-back mechanical filters. I had never heard of the under- gravel controversy until very recently. I started losing mature fish for no apparent reason and could not keep new ones alive for but a few weeks. it turns out my pH was quite low (in the 6's) and off the scale for most testing kits. After much discussion with a knowledgeable pet shop, it was determined the culprit was trapped "muck" under the gravel plates. I wouldn't say I"m diligent about vacuuming my gravel, but I'm not neglectful either. I probably vacuum and do a 5-10% water change every 4-6 weeks. The pet shop has suggested I abandon the under-gravel all together but I'm not sure I'm ready to do that as I believe the biological benefits are the same ones I grew up relying upon 40 years ago. I will be changing out my power heads for reverse-flow ones (wasn't aware of those either until recently) and keeping a much more watchful eye on pH levels. 

~Scott


----------

