i use RO/DI water .....dont know what gfo is???........dont have a phosphate test kit yest( i heard with a new system you dont need to test yet???) so far im doing weekly 5 g wc (i have a 28jbj) ......should i feed every other day for fish ??? what about my anemone its small??diAtoms---what you see on the rocks are the symptoms, but not the problem. The problem is phosphate/silicates in your water:
Use RO/DI water
Run a GFO
Test your phosphates and replace the GFO when they rise
Step up the water changes (physically removing the stuff)
Ease up on the feedings
Couple months of the above and problem solved
sweet ive been rubbing it off the rock and spraying with a syringeDiatoms will burn themselves out in a new tank, its just a natural occurence. If after a few month you still have them and/or other algae then you might want to adjust feeding, lighting and consider gfo. (granular ferric oxide). But for now I would let them do their thing, you can siphon off carefully the brown stuff just dont mix up your sand too much