PH Issues

[Kuroth]

I have a 3 Gal freshwater tank and I believe it has completed the Cycle.. It's been 6 weeks and all Parms testing well..

But my PH keeps dropping to like 6.6. I do weekly 35% water changes using RO water with a PH of 7.0.

Within a day, my PH drops from 7.0 to 6.6 and I don't know why or how to get it to stay at 7.0.

I even use a PH balancer that is supposed to keep the PH at 7.0.

Any suggestions?

 

[Back in the fold]

Don’t drive yourself crazy worrying about pH . It never changes no matter what you do . Whatever pH your water is is what it will always be . Keep checking it and see what happens but you will find that it stays the same . Don’t use those goofy chemicals and potions - they don’t work. Also , you have a little aquarium and that’s even harder to manipulate if that were even possible . Let things settle out for a week and then enjoy your aquarium.

 

[Essjay]

KH stabilises pH, the higher the KH, the harder it is to change the pH; the lower the KH, the easier it is to change the pH. RO water has zero KH (or very very little KH) so it is very easy to change the pH.
The natural processes in a tank cause it to become more and more acidic eg nitrate made by the nitrogen cycle is acidic. Because there is virtually no KH with RO water, the pH will naturally fall.


As Back in the Fold says, just leave the pH to do what it wants to do. Since the water is RO, you need fish which need very soft acidic water so a pH of 6.6 is ideal. However, with just 3 gallons there are few fish suitable for the tank size regardless of their water needs.

 

[Endlersendlers]

I have a 3 Gal freshwater tank and I believe it has completed the Cycle.. It's been 6 weeks and all Parms testing well..

But my PH keeps dropping to like 6.6. I do weekly 35% water changes using RO water with a PH of 7.0.

Within a day, my PH drops from 7.0 to 6.6 and I don't know why or how to get it to stay at 7.0.

I even use a PH balancer that is supposed to keep the PH at 7.0.

Any suggestions?

I have had success with using cichlid substrate and limestone rocks in the tank. With inert substrates my water reverts to 6.4 and any chemicals, as others have said, can bring about sudden changes but it reverts back in hours. That just stresses the fish. In my cichlid substrate tanks the water stays about 7.4 to 7.6 even with water changes. Limestone rocks do help but not immediately, it’s a gradual change until they reach a point of equilibrium with the water. You would want the cichlid substrate that claims to make the pH more basic. As a disclaimer, I’m doing this in 10 gallons or up so 3 gallons may have wider pH swings with water changes and some fish are more sensitive to that.

 

[10 Tanks]

Hello K. Trying to change the water chemistry is never a good idea. It's best to simply change most of the water every couple of days. The vast majority of aquarium fish will adapt to the vast majority of water as long as the chemistry remains constant.

10 Tanks (Now 11)

 

[Byron]

The real problem here will be finding fish suited to a 3 gallon tank. As for the pH, leave it alone, it does what it does because of the natural laws of biology and chemistry and Essjay clearly explained it.

 

[sharkweek178]

Just to sort of echo what Byron said, there isn't really a fish that should be kept in 3 gallons. Even a betta should be kept in at least a five gallon. You could keep shrimp or snails. But I don't think any fish is suitable for such a small tank.
The biggest problem with a tank this small is that it's very hard to keep the water parameters stable. When things go wrong, they go wrong fast. You'd really be doing yourself and any fish you want to keep a favor by getting a bigger tank.

 

[Ram419]

I'm using the smaller 3 gallons I have for medicating small fish or to raise fry or younger fish until they can be moved to a larger tank.

 

[Byron]

To explain how pH works. First, you/we need to know the parameters for the source water (tap or perhaps well?) on its own. These refer to the GH (general hardness), KH (carbonate hardness also called Alkalinity) and pH. If you can ascertain these from the website of your water authority (assuming you are on municipal water) this is fine. These three are closely connected. The pH will remain in the natural relative state to the GH and KH.

Second, it is normal for pH to lower in an aquarium, due to acidification. The extent to which it does, and how rapidly it does, depend upon the GH and KH and pH of the source water. A second thing is to know if the water authority (assuming city water again) adds something to increase pH; many do, as this can be temporary.

If you have another running tank with fish, what are the parameters of that water?

A couple things about testing pH. For fresh tap water, you need to ensure any dissolved CO2 is outgassed; the easiest way is to let a glass of water from the tap sit for 24 hours, then test pH. This is not needed for aquarium pH tests, or for the GH/KH should you test for those.

And, always test pH at the same time of day long-term, if you want to see what if anything is occurring. The pH can often be different in the early morning, as compared to late afternoon. So testing for a few days, always at say 10 am or 4 pm or whatever, gives you a better idea of any fluctuations day to day.