FishProfiles.com Message Forums

Looking for water chemistry help...

I have mildly alkaline/hard city water.
PH- 7.87
Alkalinity- 30.3 ppm CC
Hardness- 20.3 ppm CC

and, I am going to attempt to start softening my water for the young angelfish I recently started keeping.

I am trying the process I saw on the net of aerating about 5 gallons in a water container with a pillowcase full of peat for 1-2 weeks, and then using some of this water in my weekly water changes.

It's a 40 gal tank and I plan to change about 20 gallons/week, Anyone done similar before? and have suggestions on how many gallons of the peat adjusted water I should use to slowly lower the PH over a few water changes?

I am targeting a PH of 7.0 and will test the water, but just wondering about how many gallons it may take???

TIA

Have you considered just adding some peat to your filter media? It seems that would give you a more stable pH. I know Fluval, for one, sells peat ready to put into filters.

Degma,

Your water parameters should be fine for young angelfish. Although the conventional wisdom states that they prefer soft, slightly acidic water, this is not necessary for growing out your fish and is only preferable for breeding your fish.

I am a little confused on your hardness and alkalinity readings. If they are coreect you have very soft water, under 2dGH and just over 1dKH. Most of us who have soft water fish would love to have your water.

The following is from the FAQ on this site:

Raising and Lowering pH
One can raise or lower pH by adding chemicals. Because of buffering, however, the process is difficult to get right. Increasing or decreasing the pH (in a stable way) actually involves changing the KH. The most common approach is to add a buffer (in the previous section) whose equilibrium holds the pH at the desired value.

Muriatic (hydrochloric) acid can be used to reduce pH. Note that the exact quantity needed depends on the water's buffering capacity. In effect, you add enough acid to use up all the buffering capacity. Once this has been done, decreasing the pH is easy. However, it should be noted that the resultant lower-pH water has much less KH buffering than it did before, making it more susceptible to pH swings when (for instance) nitrate levels rise. Warning: It goes without saying that acids are VERY dangerous! Do not use this approach unless you know what you are doing, and you should treat the water BEFORE adding it to the aquarium.

Products such as ``pH-Down'' are often based on a phosphoric acid buffer. Phosphoric acid tends to keep the pH at roughly 6.5, depending on how much you use. Unfortunately, use of phosphoric acid has the BIG side effect of raising the phosphate level in your tank, stimulating algae growth. It is difficult to control algae growth in a tank with elevated phosphate levels. The only advantage over hydrochloric acid is that pH will be somewhat better buffered at its lower value.

One safe way to lower pH WITHOUT adjusting KH is to bubble CO2 (carbon dioxide) through the tank. The CO2 dissolves in water, and some of it forms carbonic acid. The formation of acid lowers the pH. Of course, in order for this approach to be practical, a steady source of CO2 bubbles (e.g. a CO2 tank) is needed to hold the pH in place. As soon as the CO2 is gone, the pH bounces back to its previous value. The high cost of a CO2 injection system precludes its use as a pH lowering technique in most aquariums (though see the PLANT FAQ for inexpensive do-it-yourself alternatives). CO2 injection systems are highly popular in heavily-planted tanks, because the additional CO2 stimulates plant growth.
----
It is a good read on water chemistry located at this link http://www.fishprofiles.net/faq/begin-chem.asp

Last edited by bob wesolowski at 19-Mar-2005 10:54

__________
"To steal ideas from one person is plagiarism; to steal from many is research."
researched from Steven Wright

Thanks all for the respones, The GH and KH numbers I was relying on were from a recent city water report. For some senior-moment reason, I was assuming my water was hard...I tested the aquarium water myself and the tests indicated-

PH - 7.9
GH - 6 degrees (soft)
KH - 4 degrees (soft)

As Bob says, Looks like I do have soft water !
I would still like to try to lower my PH closer to 7.

Would the peat still be a good way to also lower PH ?
or a bad idea since my water is already soft?
Any other suggestions?

I personally wouldn't bother with peat. I've tried using it for a short while and I've seen no change in KH or pH. I suspect that any little change caused by the peat will be shortlived as water changes will raise your KH again, and your pH too.

As Bob said, there's no problem with your current water parameters to raise an angel fish (see here and that it's only necessary if you're planning on breeding angelfish, which I guess you're not if you have only one fish. I would suggest to leave things as they are.

In any case, if you're sure that you want to lower your KH, I would still advise you to forget about peat. As you might already know, pH, KH and CO2 go together hand in hand. Your current levels of pH and KH show that your CO2 concentration is 1.51ppm. Playing with the numbers on a CO2 calculator (like the one here will show you that to have a pH of 7 you will need to lower your KH to 0.5 degrees. That's a long way to go, in my experience, and I doubt it if peat will be of any help.

There are still ways to lower your pH, but have a think if you it's really that important to you.

Degma,

This is from the Faq on this site:

Raising and Lowering pH
One can raise or lower pH by adding chemicals. Because of buffering, however, the process is difficult to get right. Increasing or decreasing the pH (in a stable way) actually involves changing the KH. The most common approach is to add a buffer (in the previous section) whose equilibrium holds the pH at the desired value.

Muriatic (hydrochloric) acid can be used to reduce pH. Note that the exact quantity needed depends on the water's buffering capacity. In effect, you add enough acid to use up all the buffering capacity. Once this has been done, decreasing the pH is easy. However, it should be noted that the resultant lower-pH water has much less KH buffering than it did before, making it more susceptible to pH swings when (for instance) nitrate levels rise. Warning: It goes without saying that acids are VERY dangerous! Do not use this approach unless you know what you are doing, and you should treat the water BEFORE adding it to the aquarium.

Products such as ``pH-Down'' are often based on a phosphoric acid buffer. Phosphoric acid tends to keep the pH at roughly 6.5, depending on how much you use. Unfortunately, use of phosphoric acid has the BIG side effect of raising the phosphate level in your tank, stimulating algae growth. It is difficult to control algae growth in a tank with elevated phosphate levels. The only advantage over hydrochloric acid is that pH will be somewhat better buffered at its lower value.

One safe way to lower pH WITHOUT adjusting KH is to bubble CO2 (carbon dioxide) through the tank. The CO2 dissolves in water, and some of it forms carbonic acid. The formation of acid lowers the pH. Of course, in order for this approach to be practical, a steady source of CO2 bubbles (e.g. a CO2 tank) is needed to hold the pH in place. As soon as the CO2 is gone, the pH bounces back to its previous value. The high cost of a CO2 injection system precludes its use as a pH lowering technique in most aquariums (though see the PLANT FAQ for inexpensive do-it-yourself alternatives). CO2 injection systems are highly popular in heavily-planted tanks, because the additional CO2 stimulates plant growth.

__________
"To steal ideas from one person is plagiarism; to steal from many is research."
researched from Steven Wright