# Big problems since adding bog wood. KH !!



## clothman

Ive had a 60in x 18in x18in community fresh water tank for 15 years and been very happy with it. No problems except the odd ancient fish dying. Even my Khuli loaches used to breed. 
In January this year I got a new carpet and had to move my tank, so I decided to change the set up of the tank. I bought a huge gorgeous piece of bog wood about 36in long x 12in x 12in. I soaked the bog wood and refreshed the water over a two week period. I then reset up my tank using about a third of my old water, same gravel, new external filter but old filter mediums. My fish looked fine but I started to lose the odd one, when I tested the water my PH had dropped to 5. I added approx 2 to 3 kg of coral sand over a week long period and this raised my PH to 7. But when I checked my KH it is only 3. I waited and it has not raised so I put 3 bits of ocean rock (about 5in long) in. This has not helped. I have also added some Aquarium salt about 6 tablespoons. 
My PH 7, No ammonia, No nitrate, No nitrite, GH 12, KH 3.
My tap water is med/hard and KH is 3 too, I had never tested my tapwater in the past but I have never had any problems in the past
Ive lost about 20 fish now and most of my plants have died. 
It would be a really difficult job to remove the bog wood but I will if I have to. But this still leaves my tap water as KH 3.
Although I wish to resolve this asap, I dont really want to resort to adding chemicals on a regular basis, I would prefer to combat this naturally and prefrably keep the bog wood. 
Any Advice? Thanks.


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## Flint

Your plants died due to the salt. I suggest removing the salt via water changes. I can't comment much on the KH but from my understanding you shouldn't have such a large gap between Kh and GH.
_Posted via Mobile Device_


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## clothman

Thanks for your reply. 
I actually added the salt this week, after reading it can increase your KH. So fish and plant deaths happened before this. I should have put a time frame.
*January:*
I put bog wood in. 
Lost a few fish.
*Beginning of Feb:*
I noticed PH low. 
Lost a few more fish
*Middle of Feb:*
Most plants dead now.
Noticed KH low. Put in Coral sand.
KH still low a week later. 
*Beginning of March:*
Put in Ocean Rock. KH still low. PH fine.
*Last week of March:*
Put the salt in (API Aquarium salt) at only half the recommend dose.
I have also tested my water with my test kit and got a local pet store to check my results with their kit.


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## RSVBiffer

Bogwood releases tannin and humic acid into the water and because of your low KH you have experienced a big drop on the pH as the buffering capacity is more easily exhausted. You need to get your KH up and you can either use one of the commercially available adjusters or baking soda, just be sure to adjust it gradually over a period of time. Systems with a high pH but low alkalinity tend to be very (dangerously) unstable so you shouldn't try to adjust the pH without addressing the underlying problem of your alkalinity.

PS The effects of coral sand on KH are dubious to say the least, coral sand is used to adjust GH rather than KH.


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## beaslbob

Kh of 3 should be ok.

IMHO you should not have increased kH with salt.

IMHO you should not have to increase kH.

If you absolutely have to increase kh, then use baking soda.

I like planted tanks and recommend those even if you have to partition the tank to protect the plants.

IME ph will rise well above 7.5 just before lights out due to the plants consuming carbon dioxide.


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## RSVBiffer

TBH Bob 3 (51ppm) is low and on the very limit of the minimum recommendations. The fact that the OP is experiencing large pH swings (from 7 to 5) would suggest that the issue should be addressed. Think to be on the safe side the level should be taken to at least 60ppm to stabilise the pH.


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## beaslbob

could be rsv.

My concern is not the actual pH swing or value but what the value represents.

To me it is the build up of carbon dioxide that is the concern.

Even with peat moss in the tank, with plants the just before liths out pH will be much higher then 7. (in my tanks above 8.4 with the api high range test kit).

that represents a very low level of carbon dioxide.

KH will limit the nightly drop, bit as long as the tank is basically a net consumer of co2 and producer or oxygen each 24 hour period, that drop means nothing.

but should the tank have a very low pH that is constant, the high co2 can result in extremely stressed fish.


Still all that is just my .02


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## RSVBiffer

beaslbob said:


> could be rsv.
> 
> Even with peat moss in the tank, with plants the just before liths out pH will be much higher then 7. (in my tanks above 8.4 with the api high range test kit).


In my own, the pH today was at 7.02 at 'lights on', 7 hours in and it is at 7.14 and at 'lights out' in 5 hours it will be <7.20 ;-)


As I understand this there are two possible factors at play here, this assumes all other factors have remained equal. The first is a large volume of water has been displaced from the setup and affected the parameters such as CO2. The second is that there is now a large piece of wood leaching humic acid into the setup. Because of these the setup has become 100x more acidic due to it having minimal buffering capacity.

I would personally say the movement in pH is a concern. 5 is very low and it is getting towards the level where the filter bacteria are no longer viable and the proportion of ammonium in the TAN would result in a sudden flood of ammonia in the system if the pH should jump back for any reason. As the KH is so low sudden swings are possible. To build up the buffering capacity of the water would be a major contribution in combating pH swings whatever the cause. 

If I were in the OPs position I would first look to gradually raise the KH to 60ppm (~3.3 dKH) and see the effect on the pH and if still low I would then raise the KH to 80ppm (~4.5 dKH). If things were still not right I would start looking at other factors. To prevent jumps in pH whilst adjusting the KH I would use a polyfilter to remove any humic acid that is released. Once the KH is in the right region I would remove the polyfilter and start monitoring the pH. I would also remove the coral sand etc to due to the affect on GH but, again, avoiding any sudden shifts in the numbers.


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## clothman

Hi guys,
Thanks for the advice so far. I have decided to try to raise my KH using baking soda. I erred on the side of caution and used just under the average dosage I found online and used one tea spoon. That was yesterday and ive just checked and it has moved up to 4 deg. I will add more gradually. Just to confirm My PH seems to be static at 7 and has not seemed to have moved for about a week now. I am a good gardener, and have tropical frogs in a planted vivarium which I have great healthy plants in. I would love a planted tank but have never had any luck they always seem to die off and I have an Interpet tropical daylight light which I change periodically. I have plenty water agitation from a spray bar and a 8 inch air curtain. I have to admit to not fully understanding about the co2 (i understand the carbon dioxide-oxygen cycle) but not ever having any tank problems in this area before I have never had to research it. I will maybe try to remove the coral sand with a gravel cleaner later on. 
Anyone want to buy a big bit of bogwood? lol


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