Tank size is a trade-off. Larger tanks require less frequent care--smaller tanks allow you to keep more tanks and work with a greater variety of fish. I have spawned several types of apistos in 5 1/2 gallon tanks. I believe the trick is having enough vegetation in the tank so the fish don't constantly see each other when they are not getting along. I think it was in Vierke's dwarf cichlid book that I read a recommendation of filling up the tank with big rocks (it's been a long time since I read it so I might not be recalling accurately) to create hiding spaces. Regarding lighting--if color rendition is not important to you, Home Depot carries 18 inch flourescent light fixtures, complete with flourescent lights) from Lights of America. They are labeled under-cabinet lights. They seem to be pretty good with plant growth. They cost $6.80 cents the last time I bought them and are about 19 inches long (just longer than a ten gallon tank).