Tropical Ph Too High?

[jrc0001]

Hey everyone,

We went away for holidays for 2 weeks and when i got back the Ph had risen from 7.2 to 8.0, tho i never had any fish in the tank but had some plants. I did a large water change thinking it would come back down, which it did for a few days before going up again, i haven't had this problem, however i have 10 neon tetras and 4 odessa barbs in the tank now, and i fear the the PH is to high for them at 7.8-8.0. i have tryed water changes and PH down but the PH keeps bouncing back up. Could i have to many plants in the tank(3ft tank with 6 plants)? Also the KH of the water is 3, i would have thought that this would have been low enough to allow the PH to change.

I have been adding the PH Down for about 4 days now and no change.

Does anyone know why this would be?

Thanks

[bettamuse]

Putting timber in the tank can help keep the ph down.

What kind of gravel do you have?
Do you have anything else apart from plants in the tank?
What kind of filter and medium do you use?



BM

[jrc0001]

Thanks for the fast reply!!!

what type of timber? any or just drift wood? and how does it help chemically?

as far as i am aware it's just plain gravel, i didn't buy grit, so i can't see that being much of a problem, however i have 2 grades, a finer grade as well as a larger.

other than plants i currently have 10 neon tetras and 4 odessa barbs, there are no other decorations etc in the tank

as for filtration i have a Fluval 403 canister with prefilter, biomax, carbon and a filter pad, i also have an UG with a powerhead.

would any of this be causing the PH to rise? i should mention that the Ph was already elevated when i added the fish

Thanks again

[Woodsy]

"midnight" black gravel, coral sand, and white rock are common causes of pH elevation, as well as some less common rocks such as limestone. An easy way to test whether your rocks (more so than your substrate) contain carbonates is to pull them out of your tank, dry them, and to test for a reaction with a few drops of vinegar. If the rock starts to "fizz" it will buff your pH. If you are going to put the rock back in the tank afterwards, make sure to give it a REALLY good wash, as vinegar will kill your fish. If you want an explaination of the chemistry of this reaction, just let me know.

[bettamuse]

Any type of timber will do it. It is the tannins in the timber that bring down the PH. This is normally only effective in a tank that has a stable PH to start with.

There is something in the tank that is raising the PH as biological wast normally reduces it.



Look for the gravel as Woodsy described.

BM