Wow ok so I tested for alkalinity and was shocked to find it at 0 ppm. Ph was low too at around 7.5. That is definitely the problem. What I dont understand is why all my corals/fish were looking the best I've ever seen, I do a water change and I get problems right away. If my alk was low, shouldn't the water change raise my levels a bit. Did around 30% change. Why was it still at 0.

Adding a buffer to the tank atm to get levels back in check and will monitor more closely in the future.

Corals are all looking 100 times better. Just a little color loss but no losses.

how is that possible to get 0 as a reading for alkalinity? don't you test from time to time and dose when necessary?

My guess is that it would take a long time to get the alkalinity down to such a low value?

i would double check those readings before you start to dose.

0ppm sounds kinda off.

I did regularly test and everytime I did, levels were in check. So I admit I did slack off on the testing for a while.

Would a sudden decrease in phosphate lower alk? Or chemi clean in the system too long? Do u guys add anything to your top off water? Can't think of anything else that would have caused this.

Got levels back in check now and corals are looking good.

can you have someone else double check your alkalinity? 0 sounds unlikely.

Maybe I read it wrong :redface: those color charts are so hard to read... Hmm I did test twice though because I was like it can't be! The first time but got the same reading again.

Which brand of kit are you using for alk?

Mine doesn't use a color chart but is number of drops till color changes to indicator color.

That's what I usually use but the last time I used those API test strips that u just dip in the water... That's all I have right now.