I have been dealing with alot of brown/red algae. Within 3 days of changing the filter cartridges, they clog up and water runs over the top. I do a 20% water change once a week. I turn the light on for 4 hours a day. The tank does not get any direct light from outside. I bought some Algone and have placed that in my filter, and i also have cleaned the whole tank, rocks, plants, and swept the gravel. Still the filter clogs. Now, i just bougt a test kit for nitrates, alkalinity, hardness, ph. The nitrate level is around 60, and the alkalinity is 300. The tank water has a brown tinge to it, not very clear. Any suggestions on how to correct these problems would be greatly appreciated!!