# Changing Substrate in Cycled Aquarium



## andrewsz123 (Aug 17, 2010)

Does anybody have any advise on changing the substrate in a cycled planted freswhater aquarium. I am looking to change the substrate for the benefit of my plants, they are way too big and i am noticing the roots are not taking hold well. I also have fish and the tank is about 3 months old. Any advise would be greatly appreciated.


----------



## redchigh (Jan 20, 2010)

I would get an extremely fine gravel and just pour it into the tank (after washing it), leaving your old rocks in place. The new gravel should fill in the gaps.


----------



## SinCrisis (Aug 7, 2008)

Smaller gravel will eventually mix to the bottom when gravel vacing is done wouldnt it? smaller rocks will end up at the bottom when its disturbed.


----------



## redchigh (Jan 20, 2010)

Ah, Gravel vac... Forgot some people still do that. 

If the gravel is too large for plants, then the smaller gravel/course sand will probably just fill in the gaps.

After a month or two you can try to get the original gravel out, leaving just the new gravel... 

Of course there's probably no problem with just taking the gravel out... The filter should be well-colonised with bacteria, and if you add several plants you shouldn't have a problem. (I would use at least a few fast growing plants..)


----------



## andrewsz123 (Aug 17, 2010)

*Thank you*

Thank you for your posts, that seems like the most viable route. Im not into my gravel it at its blue! i was thinking of what my fiance would like when making the purchase, bone head move..lol


----------



## redchigh (Jan 20, 2010)

He's probably like black sand.


----------



## SinCrisis (Aug 7, 2008)

black sand = best substrate ever.


----------



## Byron (Mar 7, 2009)

Assuming this is the aquarium in your log photos, yes, you want to remove the blue completely and not mix something with it.;-)

This is not difficult, and can be done one of two ways. You can leave the fish in the tank and just remove the existing gravel and carefully pour in the new; some do it this way, though I don't like to. I prefer having an empty tank to work in so I can arrange things without worrying about fish, plus without water it is easier to arrange the substrate, plant the plants, then fill and have less cloudiness.

A spare tank with water from the existing tank, plus the filter & heater moved over to the spare, and the fish netted out and into the spare. Then you can take your time to reset the main tank.

Dark substrates are best, both for fish (less stress=better health) and plants (visual, they look nice with a dark substrate and background). This is a 29g so not too large to make a plant substrate like Eco-complete or Flourite possible, but plant small-grain gravel or sand will also work. Just make sure it is dark, whether black, dark brown or gray, or natural.

Once the substrate and plants are in, fill and add water conditioner, then move the filter and heater back and the fish. Don't wash the plants or any decor, or filter; plenty of bacteria will have colonized these, plus the plants assimilate ammonia greedily.


----------



## andrewsz123 (Aug 17, 2010)

Byron,

Sounds great thats what I was going to do. In reference to the eco complete I was reading that initially that substrate increases the PH for about 2 weeks until it levels off, is this correct? How long after adding water conditioner does to take for the chlorine to leave, subjust to the water temp can I add the fish back to the tank immediately?


----------



## SinCrisis (Aug 7, 2008)

When i added eco complete to my tank my ph only rose by .2 Unless your ph is already really high, you should be ok with adding it without worrying about ph spikes. It does make your water cloudy for a while though since theres a lot of dust, even if you rinse them a lot.


----------



## redchigh (Jan 20, 2010)

For some reason I was thinking your gravel was too big rather than it being blue..

Actually in response to sincrisis, if you water is high-ph and hard, the ph probably won't change at all... Soft water would me bore likely to have a large ph spike...


----------



## Byron (Mar 7, 2009)

andrewsz123 said:


> Byron,
> 
> Sounds great thats what I was going to do. In reference to the eco complete I was reading that initially that substrate increases the PH for about 2 weeks until it levels off, is this correct? How long after adding water conditioner does to take for the chlorine to leave, subjust to the water temp can I add the fish back to the tank immediately?


I've read Eco-complete will raise pH marginally at the beginning, but I've not personally used it. I doubt it would be a significant change. When I set up new tanks or re-set existing tanks the pH is initially higher than the existing tank but that has never casused a problem. When I transfer the fish I use a 2g bucket half filled with water from the existing tank, the fish are netted into the bucket (several at a time), the bucket is then filled up with water from the new tank, and after maybe 5 minutes the fish are netted in to the new tank. Some believe this fussing is unnecessary. Many authorities suggest that fish can manage a pH change of up to 1 degree, that is as an example from 6.0 to 7.0, though in my case the change is less, maybe .6 or so. A one-time change is not the same as fluctuating.

Water conditioners work immediately. As long as there are lots of plants, there should be no problems.


----------



## SinCrisis (Aug 7, 2008)

my water is super soft due to a softener system, my ph, is 7.6 out of the tap and was 7.8 when i first had eco-complete for about a month with steady 15% water changed each week. Then it settled down and I added driftwood so now my tanks at around 7.3-7.4.


----------

