Is this from dosing H2O2?

[Randy Holmes-Farley Verified Community Expert]

I don’t think it likely that hydrogen peroxide persists in a reef tank days after it is dosed. Too many things that break it down.

 

[GARRIGA]

I don’t think it likely that hydrogen peroxide persists in a reef tank days after it is dosed. Too many things that break it down.

In my 20H test tank I've dosed as much as 250ml (over the coarse of the day) and it was gone by the next morning. Never saw any trace the next morning on any of days of testing. Ran these experiments for over two months. Only fish and inverts and tons of GHA along with pom pom macroalgae and none seemed affected by any dosage. Although GHA in the tank started turning white yet that which was growing on the pom pom under the grow light was thriving. Did run my Fuge light 24/7 therefore not sure if that accelerated the decomposition.