Super high pH, don't know why

[Delphinus]

I'm running my 65g FW on tapwater (whichtests out at pH=7.5 and KH=11).

Substrate is a mixture of Flourite, Eco-Complete, and some kind of lava based substrate which is supposed to be good for plants. There's also several pieces of Malaysian driftwood.

I was about to look into getting CO2 running again, and thought I would take some tests to establish a baseline before adding any.

The pH probe shows pH=9.0.

Not believing that, I went out and bought a dripwise pH test kit and it tests out at 8.4.

What would be pulling the pH up so much?

I could filter some peat moss to bring down the pH, but I wonder if there's something I should be taking out of the tank as well.

[Aquattro]

Tony, what does your tap water measure?

[Delphinus]

The pH probe told me 7.6. The dripwise test kit showed me 7.4 (the lowest number on the scale, it reads from 7.4 to 8.8 or something like that). The pH probe is old and I was thinking it might be shot, but it tells me plausible numbers for the SW tanks (8.2, 8.3 and 8.4). But I hope it's wrong on the 9.0 reading, that seems way too high. Even if it's wrong though, it seems clear that something IS pulling up the pH somehow.

[Myka]

Are your plants or fish stressing at all? If not, I would leave it alone unless you can lower it and keep it steady. It's better to be steady at 9.0 then wavering between 7.0 and 9.0. What's your temp at? The CO2 in itself will lower the pH too, so keep that in mind as well.

[Delphinus]

No, I don't think any of the fish or plants are stressing. There were a handful of neons added on the weekend that have been dropping off one by one but I've always heard neons are like that (one actually was DOA in the bag by the time it was home). I hear that neons like a pH range of 5.5 to 7.5 though so maybe this is the problem.

Yeah, I was thinking I could just add CO2 and the pH will probably fall to a more "normal" looking number but I'm concerned that there's something else going on here that I should try to find out about.

It's weird. I read up on lava substrate, Flourite and Eco-Complete and the claims there are that they are inert and won't affect pH. I read up on Malaysian driftwood and people were complaining about unable to RAISE pH because they lowered pH so much. What's left? The food I feed? The water evaporates and becomes way too hard? I practically did a 100% water change two weeks ago (long story, but basically had to do a tank reset - between the 200 Ameca splendens I kind of let get the population get out of hand over two years - and the two containers of fish food that got dumped into the sump - my 3 year old likes to "help" and this apparently happened when I was at work during a diaper change of the 1 year old so no adult noticed this happened until I was home hours later and the water was all smoky milky white smelling like a sewer and don't get me wrong I love my kids and parenthood is a wonderful adventure and blah blah blah I wouldn't give it up for anything it's awesome and he meant well by it and I really kind of don't want to talk about it but it did give me the kick in the rearend to get on with netting out those incredibly pregnant livebearers and take them into an LFS which is something I should have done way sooner than this anyhow). So um. Yeah. What was I talking about? Right, pH. pH high. Me no understand why pH so high.

[Aquattro]

Originally Posted by Delphinus

pH high. Me no understand why pH so high.

Too much hydroxide...