how much h202 for a 5 gallon bucket

just started some dwc bubble buckets wanted to know how muck should i put in 5 gallon bucket with about 3.5 gallons of waterand does it affect ph ,ppms and how does it help plants?

1/4 ratio

As a preventative I add 50-75 ml per 100L. I used it to keep res clear of algae. I have started to use pond zyme with better success. Well not sure if better yet but its cheaper lol and res was crystal clear.

For about 3.5 gallons I add about 35ML of the 3% H202, but waterdawg above is correct pond zyme is better.

I use pondzyme / aquashield too