reducing pH for tetras

tedr108

Lifetime Charter Member
Lifetime Member
Nov 21, 2007
514
0
16
Los Angeles, CA
I'm in the process of creating a 29G non-CO2 tank that will house mainly tetras -- probably cardinals for the most part, but may add in a few others.

I would like them to be in a comfortable environment and feel that I should reduce my local water pH from 8.1 to somewhere around 7.0, since most tetras prefer more acidic water. I've read up on reducing pH and figure I can do one of 2 things: 1) put peat pellets in the filter or 2) get some pH reducer, along with some sort of buffer. My local water GH is typically around 20, and my KH is usually around 3 or less. I'll be cutting down on GH with RO water -- maybe to between 8 and 12.

I like the idea of the peat pellets, as long as they don't need to be replaced every couple of days. I would like to get to the point where I won't have to monitor pH very often. Perhaps with a non-CO2 tank and the lack of water changes, that won't be a problem. Any recommendations for reducing pH would be appreciated. Or, perhaps 8.1 pH is no big deal and the tetras will be perfectly fine -- I wouldn't mind that one, either! :)
 

aquabillpers

Lifetime Charter Member
Lifetime Member
Jan 24, 2005
639
3
18
tedr108;28445 said:
I'm in the process of creating a 29G non-CO2 tank that will house mainly tetras -- probably cardinals for the most part, but may add in a few others.

I would like them to be in a comfortable environment and feel that I should reduce my local water pH from 8.1 to somewhere around 7.0, since most tetras prefer more acidic water. I've read up on reducing pH and figure I can do one of 2 things: 1) put peat pellets in the filter or 2) get some pH reducer, along with some sort of buffer. My local water GH is typically around 20, and my KH is usually around 3 or less. I'll be cutting down on GH with RO water -- maybe to between 8 and 12.

I like the idea of the peat pellets, as long as they don't need to be replaced every couple of days. I would like to get to the point where I won't have to monitor pH very often. Perhaps with a non-CO2 tank and the lack of water changes, that won't be a problem. Any recommendations for reducing pH would be appreciated. Or, perhaps 8.1 pH is no big deal and the tetras will be perfectly fine -- I wouldn't mind that one, either! :)

The GH of water has no effect on the pH. The buffering capability, or KH, is the main determining factor.

I am a bit surprised that your pH is 8.0 with a KH of 3. I'm not saying that it's impossible, but I'd expect a lower pH. Are you sure that your test kit is accurate? Are you testing the water directly from the spigot or are you letting it sit overnight? The latter is preferable for public water.

As far as the fish are concerned, tetras do quite well in alkaline water. Many of them are bred in the US, in Florida, using whatever water is available.

Good luck!

Bill
 

Carissa

Guru Class Expert
Jun 8, 2007
678
0
16
Personally I wouldn't bother messing with it. I have tetras that I've kept in my naturally super soft water, but also I've added lots of GH for my plants, sometimes I've added KH, and I've never seen much of an effect on them in particular at all.
 

tedr108

Lifetime Charter Member
Lifetime Member
Nov 21, 2007
514
0
16
Los Angeles, CA
Thanks, Bill and Carissa. I'll definitely give the pH 8 water a try in my tetra tank -- it would make my life easier.

Out of curiosity, a number of sites on the web (probably most of them selling something) talk about getting your pH more acidic and your water softer for tetras. Why all the fuss, if it's no big deal? Is this a carry over from the old "wild caught" days? Or, are they just trying to make some money? Honestly, if the fish would be happier (not talking just survival here), I would be willing to lower the pH. But, if it makes no difference, why bother?
 

VaughnH

Lifetime Charter Member
Lifetime Member
Jan 24, 2005
3,011
94
48
85
Sacramento, CA
If you are doing a non-CO2 tank, with the lower light intensity that is required for that, you won't be doing water changes very often at all. So, mixing RO water with the tap water, to get a lower pH/KH isn't that difficult or expensive. If you really do want to go with lower pH that is the way to do it. Just don't add more salts to the water to drive down the pH. Doing that is counterproductive.
 

aquabillpers

Lifetime Charter Member
Lifetime Member
Jan 24, 2005
639
3
18
tedr108;28451 said:
Thanks, Bill and Carissa. I'll definitely give the pH 8 water a try in my tetra tank -- it would make my life easier.

Out of curiosity, a number of sites on the web (probably most of them selling something) talk about getting your pH more acidic and your water softer for tetras. Why all the fuss, if it's no big deal? Is this a carry over from the old "wild caught" days? Or, are they just trying to make some money? Honestly, if the fish would be happier (not talking just survival here), I would be willing to lower the pH. But, if it makes no difference, why bother?

That's right, why bother? :)

With some species, a lower pH and/or GH might be necessary for breeding, and maybe to meet the special requirements of wild caught fish, at least temporarily.

I still question your pH reading. It seems very high for water with a KH of 3. But maybe I am wrong.

Bill
 

tedr108

Lifetime Charter Member
Lifetime Member
Nov 21, 2007
514
0
16
Los Angeles, CA
Thanks, Hoppy, I'll plan on that.

Yes, Bill, I'm going to leave some tap water out over night and test my pH & KH in the morning. My KH test kit has been calibrated. I don't have any calibration solution for my pH test kit, unfortunately.