capper

We have 3 tanks at present. Our largest is a 46 gallon with lots and lots of guppies, guppy fry, several kinds of tetras, a couple of platties, a pleco, some cories, and lots of shrimp. I haven't checked the water in a long time until tonight. When I checked it, our 46g tank had the highest pH level I've ever seen. It was about 8.6 while our other tanks were in the 7.4 to 7.8 neighborhood.

First, I can't understand why the change. Second, should I do anything about it? If so, what?

armadillo

8.6!!! Man, I thought we had it bad with our 8.0 out of the tab!

Here's what I'd do (but only what I'd do, no idea if they're all good ideas):

- I'd revise my fish' pH requirements, species by species. I'd also look for signs of distress. If some fish are meant for under 7.0, or if there are some unexplained behaviours, then I'd decide to do something about it with chemicals from the LFS. Otherwise, I'd steer clear of the chemicals, you'd be putting your finger in a vicious circle of eternal pH monitoring and adapting, with lost of unwelcome variation for the fish.
- I heard that some types of substrates can bring your pH up. Have you changed (part of your) substrate recently, or added a decoration? The solution would be quite simple then: to go back to what you had.
- Some driftwood brings your pH down in a more gradual and natural way than chemicals would. I have no direct experience of that, though, so I don't know how long it takes, whether it brings it down drastically, and how long the effect lasts for. Driftwood seems to have changed sweet nothing in my tanks is my personal experience.