I added borax to my intex pool the begining of the season and I've not had the mustard bloom this year either. Its been too long since I did it to remember how much I put in my 6500 frame pool, but I know that is the thing that I'm doing diffrent this year and its working. I'd advise all kiddy poolers to try this in the begining of the season and see if it doesn't work for them. Kimrst