pH shooting up

[alemone]

My pH went drastically up all of a sudden as you can see. What did I do? Changed my Phosguard and carbon. I can't figure out what happened!

[badonkadonk]

That appears to be an electrical artifact of the probe (most likely) or the meter. Chances are the actual pH didn't change. Try checking the probe connections and recalibrate.

[alemone]

I think it's real. It happened the moment a put the containers with the new media back and started the media reactor.

[badonkadonk]

The rate of rise seems too great, almost sudden, to attribute to a change in water chemistry unless you dumped in some base - and even then, there would be a gradual drop back toward previous conditions. Carbon has little to no effect on pH, phosguard would have a small and more gradual effect.

[alemone]

I know that neither should have any significant effect on the pH. I started wondering if the phosguard was contaminated or even counterfeit! I think I got it from Amazon though. The water turned cloudy from (presumably) precipitated Ca, which again makes me believe there was indeed base in the media.