Starting to have a problem with 12G biocube

[XDLE33544]

Hello everyone.
I have a 12 gallon biocube up and running since just before Xmas last year. I've replaced the bio balls with live rock and mod'ed the inlets on the left side of the tank (if your looking straight at it) so that the top slats/inlets work like a surface skimmer which sorta solved my first problem which was a brown coating on the surface.

I have a fair amount of live rock, 2 or 3 snails, 2 small crabs and a small shrimp. I also have 2 clowns, and another small fish who's species escapes me at the moment.

The big problem I'm starting to have is a green grass type algea growing off the rocks and now in the sand and on the back wall. The second problem I'm having is a red, and some blue/black thick algea growing on the rocks.

I run the lights (Moon light, dawn, and daylight) to match the real light cycles of a day. That may be too much. I also feed them 1/2 to 2/3 of a cube of that frozen shrimp from Spirulina 2 times a day, maybe too much as well. I do a 1 to 2 gallon water change every week and half.

Any advice would be greatly apprciated.

[panmanmatt]

Well being as you already know your light cycle is too long and you're feedings are too heavy I would start by correcting those 2 things.

I would also increase the water changes to weekly ones. Won't hurt to start rinsing your frozen foods in FW first before feeding it to the tank, this will help decrease the amount of nutrients you are adding to the tank.

[XDLE33544]

Thx Pa, I've also been told that putting in a bunch more snails and crabs would help as the crabs would eat he grass looking algea?? You think there's any merrit to that