Green tint

[steve1793]

hello
i have never had problems in the past. i have a nature 2 cartridge and usually can keep my chlorine low.
recent check has everything in the middle range (i dont have the numbers with me)

never had this problem, the water has a green tint to it. i boosted the chlorine a little, but i have never had to do that in prior yrs.

the only thing i can think is different is i used an algaecide from a cheap discount store. should i get better stuff???
any suggestions? i usually shop hard for the lowest price

thank you in advance