How to lower PH
 

This is embarassing :redface: , but it has been a while since I have to do this. How do you lower PH? Is it vinegar??????

What's your pH at these days?

My PH in my FRESHWATER tank is around 7.5. I have Cardinal Tetras so I want to reduce the ph to about 6. I could go out and buy the stuff from the LFS, but I am too cheap so what is the home remedy.

If you're talking household stuff then I guess vinegar would work, although I've never used it before.

6.0 is a little low don't you think? I'm sure you'd be fine with 6.5, or even neutral 7.0 for the cardinals IMO.

JMHO, but I would leave pH alone. Once you start tinkering with pH, you also alter the alkalinity of the water. If you aren't paying attention to the alk while lowering the pH, you could really upset the balance and get large daily pH swings. IME, tetras don't mind a pH of 7.5.

7.5 is in an acceptable range. Though not optimal, the fish will adapt to it and be quite healthy and happy. If you are concerned and check the ph of your water supply. If it is lower than 7.5(ish) it is probaly something in your tank such as a rock or decoration that is causing it. As for vinigar, I don't recommend it or playing with buffers. All you will get is unstable ph that will swing wildly and stress the fish far more than a constant ph level even though high.

The tannins released from a chuck of mopani wood should drop the pH a bit. Of course the water will be brown, but tetras are from that environment anyway. Soaking it first for a week removes a lot of this coloring. Just a thought...

Our tap water was around 6 the last time I checked a couple of years ago.
Is it not anymore? The only way I could raise it was to add crushed coral to the tank. The water here was always perfect for tetra's without any help.






Jeff

If you have plants you can inject co2. It lowered mine from about 8 to 6.5. Plants grew like they were on steroids :)

Walter

Thanks for all the wonderful inputs; I am going to leave it and since I was going to decorate the tank, I might as well stick a pc of mopani wood in as per Brad. Thanks guys.

Sorry late chiming in here. Have you tested your tap water?

Most regions in the lower mainland have a sub 7 pH (mine is 6.5 ish) out of the tap. Since bioload in most FW tanks tends to deplete alkalinity and lower pH, Im thinking that you might have something in your tank that is releasing carbonates...

What sort of substrate do you have? Some types of mixes have bits of crushed coral or shell to 'stabilize' pH and coincidentally, pH around mid 7 is where they often balance out to IME.

I have kept a school of cardinals for over two years at pH around 7.8 and they are thriving.

You only need to lower the pH to try to breed them. When I did that, one of them died.