How can I reduce the effect co2 has on my pH?

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hortoholic

Aquarium Advice Apprentice
Joined
Dec 23, 2009
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I am thinking about adding co2 to my plants using a DIY system. My current pH is at 6.8 what can I do once I add the co2 to prevent it from reducing my pH too much. If I add this I am worried that it will cause my pH to crash? Is there anything I can do? or do you suppose my fish will be ok? It is a freshwater tank.

If anyone knows about this it would be appreciated very much,

hortoholic
 
I'm kind of in the same boat and my thread might be of some help: http://www.aquariumadvice.com/forums/f12/plant-safe-ph-buffer-135041.html

pH is a very tricky thing....really depends a lot on your GH and KH on how stable it will be. Freshwater fish are pretty hardy when it comes to pH they can live at as long as its stable. Rapid fluctuations in pH can even wipeout freshwater tanks.

The best way to keep a stable pH is not to mess with chemicals but use buffers, but I've found no plant safe pH buffers as my thread illustrates.

The only advice I can give you is trial and error with constant pH monitoring or put in a RO/DI system and still keep a close eye on pH.
 
If your pH is already 6.8 then I don't know how much lower adding CO2 would take it. Certainly the effect will not be nearly as drastic as if your tank was pH 7.6 or something like that.

The short answer as to what to do about it is, increase the buffering capacity (KH) of your water. I would avoid adding chemical to do this like the plague; far too easy to screw up and have wild pH swings.

A much safer, more stable, method would be to add crushed coral to your filter, if that is at all possible. Easy to do with canister filters, and easy with quality HoB filters like AquaClears. If you use a HoB filter that uses all-in-one inserts, or if you use a biowheel, sponge, internal, or undergravel filter, you might be in trouble. In that case, probably all you could do would be to put a bag of crushed coral in the tank itself somewhere.
 
I will try adding the co2 and see what happens to the pH. I know this may sound dumb, but if it happens to throw my pH off a little, would increasing the aeration to let the co2 disperse and stabilize it over time or would changing the water be best? I don't think it will bring it to low either. It's pretty stable as of right now.

First I will try without and then with to see the difference

i'll add some crushed coral and see where it takes me.

Thanks for ally the help!
 
I will try adding the co2 and see what happens to the pH. I know this may sound dumb, but if it happens to throw my pH off a little, would increasing the aeration to let the co2 disperse and stabilize it over time or would changing the water be best? I don't think it will bring it to low either. It's pretty stable as of right now.

If the pH drops due to your CO2, then all you need to do is stop with the CO2 and the pH will stabilize by itself back to its old level in less than 24 hours. Increasing aeration would definitely accelerate that process.
 
whats your gh and kh? in most cases i wouldnt even worry about it. as long as you have 2 degrees of carbon hardness or more you should be fine. the co2 lowering the ph isnt the same as lowering the ph with peat.
 
My GH: ~1.7dh

kh appears to be 30 but the fish I have seem to be thriving. And our water is pretty soft.


I am sorry for the late reply,


hortoholic
 
If KH is 30 your pH isn't going anywhere. :lol:

For what it's worth, my KH is 2 and I've never had a massive pH fluctuation from my DIY CO2.

Edit: Just realized you probably meant ppm not dKH. That puts you at almost 2 dKH, which is about what I have.
 
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