High Alkalinity and low-normal pH


New Member
View Badges
May 11, 2021
Reaction score
Review score
+0 /0 /-0
I have a 65 gallon and it’s been set up for a few months now. I had two clowns, blue sided wrasse, orange spotted goby, Pygmy dwarf angel and some inverts as well as some corals. I did a water change last night and then tested everything because I had an order from WWC coming today. My Alkalinity tested at 22 dkh and my ph was about 8.0-8.2. I tested with the API master reefer test kit and the High Range pH test kit. I now have 4 dead fish and a few dead corals. I used Red Sea coral pro salt and RO/DI water from my LFS. Why is it so high? I moved all the living stuff into my smaller 10 gallon until I can figure this out. What shouldn I do?

Randy Holmes-Farley

Reef Chemist
View Badges
Sep 5, 2014
Reaction score
Review score
+0 /0 /-0
Arlington, Massachusetts, United States
I doubt either of those things killed fish, but if either did, it was the very high alkalinity (if real) . The pH is fine.

Do you have any of the "RO/DI" water? measure it for alkalinity.

The common way to very high a k is tap water (with its own alkalinity) plus a high alk salt mix.

What is your most favorite type of shrimp for your reef tank?

  • Peppermint Shrimp

    Votes: 24 4.6%
  • Banded Coral Shrimp

    Votes: 48 9.2%
  • Snapping or Pistol Shrimp

    Votes: 49 9.4%
  • Harlequin Shrimp

    Votes: 47 9.0%
  • Scarlet Skunk Cleaner Shrimp

    Votes: 158 30.2%
  • Blood Red Fire Shrimp

    Votes: 113 21.6%
  • Sexy Anemone Shrimp

    Votes: 33 6.3%
  • Camel Shrimp

    Votes: 1 0.2%
  • Other (please explain)

    Votes: 12 2.3%
  • NO shrimp in my tank

    Votes: 38 7.3%
Chaos Aquaculture