By yellow I am guessing you mean the honey gouramis. I have a trio of them. I'v ehad them a little over a year now, but just recently moved them into this tank; they were in one of my 10-gals.
I am using a Flora-Glo flourescent bulb. Don't know the specifics of it really, just that it's supposed to be good for plants! LOL
Do you think it's over planted?