Crazy high alkalinity

Gaven · Jul 3, 2016

My alkalinity has been in the 15's for a while now (dKh) and almost all of my corals look like they're dying. All of my other params look fine, and I've been doing a lot of small water changes lately that haven't affected the alk at all. The guy at the fish store said he was surprised there was anything alive in my tank. I need some advice on getting this down. It had pretty much always been high, and I thought it was the crushed coral substrate that I used to have, but I moved everything to a new tank with no crushed coral about a year ago and it has only gotten worse. Please help!

Downbeach · Jul 3, 2016

What salt mix are you using? If a high alk type, i.e. Reef Crystals, you might want to start using a regular salt mix, i.e. plain IO. What is your SG, and what are you using to measure it with? Are you using a pH buffer? If so, that is where your elevated levels of alk are coming from.

Gaven · Jul 3, 2016

Thanks for the quick response. I am using instant ocean and I tested my RO water salt mix and the alkalinity was fine. I keep my salt at about 1.026, measured with a refractometer that I get callibrated every couple weeks at the pet store, and I don't use any buffers. I think it could be the rock that is causing the problem, because that is the only thing consistent between the two tanks. I appreciate any advice you can give.

Randy Holmes-Farley · Jul 3, 2016

Is it artificial rock?

Gaven · Jul 3, 2016

No, it's all real love rock

Randy Holmes-Farley · Jul 3, 2016

Real calcium carbonate rock won't be pushing up the alkalinity.

Randy Holmes-Farley · Jul 3, 2016

You are using 0 ppm TDS water for top off? Tap water can boot alkalinity.

Gaven · Jul 3, 2016

I only use reverse osmosis water in my tanks. I don't think that any of my rocks are artificial, they look real but I didn't buy them, they came with the tank when I bought it.