Realllllly low pH in QT tank...Can't figure this out

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Originally Posted by GreenSpottedPuffer

Yeah thats exactly what I thought. I have never had PH go below 8, so its new to me and I really have no idea how it could go so low. Im worried about the fish even though they both seem fine.

I may try AGAIN to calibrate the monitor or maybe its broken. But I did test manually as well and get the same results. This morning its reading 5.91 and alk is 30 mg/l

I thought this was way too low for saltwater fish and that by this point they would not be looking too good.

I was thinking of using a filter bag full of something like crushed coral to see if that stabilizes the PH at all. Is this a bad idea for any reason?

That still might not solve the problem. The CC should bring the ph up, but I would bet that as soon as the cc bag is removed, the ph will likely crash again, which means you haven't really solved the dilemma, just hidden it beneath the surface. Sounds to me like some kind of buffer is bringing it down.