Help with PH please

[qprneil]

hi there i live in the uk and i have a 22 gallon community tank and i have just tested my water and my ph level has rocketed to 7.8!!! My ammonia and nitrate levels are fine its just the ph level. How do i lower the PH?? I have some dirftwood and a few rocks in the tank if this helps. I asked my LFS and they suggested using boiled water in the tank. Would this do the trick and if so how much and how often.

Thanks for any replies.

 

[OrionGirl]

Why do you want to reduce the pH?

I ask because a stable pH is always better than a specific one for most fish. A few fish, and the intent to breed soft water fish changes this, but for a standard community tank, you're better off leaving the pH where it is.

There are tons of products out there to chemically change the pH, but their effects are temporary. The pH will be modified, but won't stay at the new level for long, and will jump back to it's previous level. This jump is hazardous to fish, and can kill them.

Using RO water in mixture with your tap water will reliably lower the pH, but RO is not the same as boiled (which I am suspicious of...Don't think this method will actually work. Distilled water would, but boiling water and distilling it are different processes). RO water can be purchased, or you can buy a unit and filter your own. Costly, especially if we're talking about a community tank. The amount of RO water vrs tap ratio is something you'll have to experiemtn with, since it is dependent on your local conditions (pH, GH and KH).

Many people will use peat in their filter to reduce pH. This also depends on pH, GH and KH, and will result in a tea-colored water.

CO2 injection is another method, but is recommended only for planted tanks.

Once more, a stable pH is much better than a specific one.

HTH

 

[wetmanNY]

Orion Girl has the right idea.

About boiling water to reduce some of the carbonates that are buffering it, which are keeping the pH very mildly on the alkaline side: heating the water drives off gases, which includes carbon dioxide. As the dissolved CO2 is depleted, soluble bicarbonates (sodium bicarb dissolves, right?) convert to carbonates and they precipitate out. The carbonates are the white cakethat forms in the teakettle.

If you let the briefly boiled water settle, (long boiling doesn't do more softening) and then pour it into another container, you'll have partially softened water. Caution: it will be depleted in oxygen and won't support fish till it's been aerated overnight.

The reason you have to decant the water is that, as CO2 diffuses back in from the atmosphere, the carbonates will begin to dissolve and you're headed back to where you started from.

So that's why at the lfs they said, "Boil up some water, mate."

 

[OrionGirl]

Would boiling be a very long term solution? Sounds like it might result in swings as well, just more gradual ones. Guess then it would depend on how frequently water changes were performed.

Thanks for the info!

 

[wetmanNY]

Yes, boiling is a permanent partial softening, as far as it goes. You have to get the water away from its precipitated carbonates, or they'll act just like the crushed coral in a filter: they'll raise the KH again.

Only carbonates are affected. Other elements in the general hardness ("GH" test) aren't affected: any sulfates, any chlorides, any phosphates etc. They aren't part of that carbon dioxide/ carbonate/ bicarbonate equation.

Soft water is unbuffered. Therefore its pH is inherently more flexible. Thus the acids introduced by metabolisms-- carbon dioxide is the major one-- will depress the pH, with little bufering or "alkalinity" to stabilize it.

Lots of acid= fast sharp drop. Little acid= slow downward drift.

 

[zmaj101]

leave it alone!

By far the best thing you can do is leave your pH alone. As long as it remains stable at 7.8, you're fine. I've seen too many people kill off all their fish by constantly tinkering with their pH. Up here in the mountains of Utah water comes out of the tap at about 8.3. I've found that fish can adapt just fine to parameters outside their ideal, although sometimes they won't mate. However, they cannot adapt to constant changes and that's exactly what you'll get by adding chemicals or boiled water every other day.