OK this is REALLY strange. Have an established 65 gallon with a sump. One
Large Goldfish and a few plants in there he won't eat. Bad case of Blue
Green algae. Used peroxide many times in many tanks and never had a problem.
Treated this one this morning and left for most of the day.

Came home and everything looks great. Even notice less algae. Couple of
hours latter he wife about panics. Looking through the tank from one end to
the other the far wall is RED and I mean RED! Dip out some water and water
is very clear.

Stand in front and you see red only where the overflow box hangs or where it
is dark. Got to be the strangest thing I have ever seen. Goldfish seems fine
and nothing noticeable. Anyone have any idea? Sun is low and house is a bit
darker and I think that has some bearing on it but I can't figure out why.
May try to photograph this.