water change question: how much is too much?

[goinbroke]

since my green hair outbreak after my anemone died i've been changing my water twice a week. i have a 75gallon display with a 30 gallon sump. probally 90gallons total. sundays(monday this week) i do a 12-16 gallon change and wednsday i do a 5 to 8 gallon change.
is this too many changes in one week? tank is looking better then it ever has! just dont know when enough is enough? thanks.....james

 

[valgae]

depends on your bio-load. do you test phosphate/nitrate? then again if it works don't change anything. try decreasing the water change amount by a gallon a week, maybe you could gradually get down to one water change.

 

[elijaher]

You can do up to 50 percent water change.