Water Changes Causing Green Water?

[karin]

Hi there.

I have a couple questions.

I have a relatively new 60 gallon tank up and running, cycled since the end of March, lightly stocked, stats with API test kit all great and consistent with a Ph of 8 and NitrAtes at around 40 ppm.

EVERY time I do a water change (20% weekly), the tank water turns green, but clears within two days to crystal clear. I do have a UV sterlizer too. Seems that this is not the normal "green water" problem and I'm not certain it is a problem at all.

Should I worry? Do something different? What is happening?

 

[stuuk1]

When you replace the water, is it kicking up that c*ap from the bottom?

 

[waterdrop]

Maybe the tap water's got algae and it takes the UV light a bit to knock it out. (not really meaning this to be a serious likelihood...) Maybe you just have a lot of light and some algae spores come in with the tap, hatch out and then are knocked out by the UV.