Last week I set up a 10 gallon dirted tank with rotala rotundifolia, ludwigia repens, hornwort, moneywort, cryptocoryne, and dwarf sag. It's starting to grow a lot of diatoms and green hair algae on my plant leaves (mostly on ludwigia repens). My lighting is 840 lumens, on for 10 hours a day and no ferts. The plants are growing pretty well. The algae seems to be mostly on the older leaves, Brand new leaves don't have algae. I thought it was healthy plants = no algae?? Is the algae part of the process or do I need to change something?