KH, CA, and PH?

[BlazinNano]

Aquarium store owner diagnosed it.

Nothing against the store owner but @Randy Holmes-Farley is extremely knowledgeable in parameters and the chemistry of aquariums.

Where are you getting your RODI water and Saltwater? Are you making it or buying it from the LFS? Have you checked the PH from new water before it is added to your tank?

I didnt see if you are dosing anything like kalkwasser or calcium or anything else.

 

[GHD1959]

KH of 7.3, pH below 8, and Ca of 390 are all perfectly acceptable values.

Are you still having trouble with fish? Why do you think it was oxygen related? Any water movement, as in powerheads, in the tank?

Loads of water movement.

 

[GHD1959]

While I think many tanks have low O2 at night, I would not assume you can diagnose it by kit nor that it is likely your current issue.

I appreciate all your help.

 

[GHD1959]

you assume anything sold is useful?

Absolutely not

 

[Randy Holmes-Farley]

My suggestion is if you are suffering fish loses, that some other explanation (e.g., disease, ammonia, etc.) is more likely than low O2 in a tank with lots of surface movement.

 

[GHD1959]

I'll recheck ammonia.... thanks