I thought that too until I changed the bulbs in my 10 gal. I now have 3 wpg in that tank, no CO2, very minimal algae and my plants are very green.atmmachine816 said:It's necessary once you hit 2wpg and over because you will have TONS of algae. Personally if you do it right you will not have any problems and of couse if you spend the mega bucks on a pressurized one well then your'e in good shape, and you have lots of loose money. I'm going to use it because I RREEALLYY want a planted tank, now if I put fish in it, that's a different story. I haven't decided on that yet and won't until I have it the way AI wnat it, then maybe I will.