I have chaeto in both tanks. theres a aquaclear modified to house chaeto. I have an abundance of cleaners (snails, crabs, etc). I have a 5600 cfl bulb on the sump and one on the 20g (to cheap to put AI's on the 20) there are no dead fish. I do water changes with ro/di water every 2 weeks or so. I've limited the light to just 8 hours a day (and thats with 2 AI Sols)...I'm pulling my hair out here and not the green kind!
I also used chemiclean a few months ago. that only helped for a few weeks. I'm constantly cleaning the glass on both tanks also!