Peroxide in aquarium?

[UkiahTheTurtle]

Can I use peroxide directly in my aquarium to kill nuisance algae my tank is a 20 gallon reef tank with fish and inverts

 

[Jay Hemdal Verified Community Expert]

I’ve been running some tests and I’m not really impressed - a constant level of 5 ppm nuked the biofilter in a FW tank. I could kill Valonia and GHA in a marine tank, but it just shifted to another, dark green species that the peroxide didn’t kill. As soon as I stopped the peroxide, the algae came right back.
One thing - you can buy peroxide test strips on Amazon that really help track dosing.
Jay