What Lighting is best for my 20 Gallon saltwater tank?

Question

I have a 20 gallon saltwater tank - Set upfor about 5 months now. Cycled perfectly with Damsels and live rock. I replaced the damsels with a pair of tomato clowns. I use 2 Whisper 30 power filters and I have the CPR60 Protein skimmer. The water conditions seem relatively fine with a slight increase in nitrates and ammonia (thinking I may be still cycling). I have 10 lb's live rock and in addition to the clowns, I have a black sea urchin and a recently added sea anemone.

My Question is: The sea anemone is fed brine,krill mix and started out looking great for 6 days now. Today it looks retracted and no longer translucent brownish but rather a slightly shriveled greenish.

My lighting is only 2 15W flourescent. I suspect this is the issue but I would rather not go with an expensive and HOT metal halide (space and toddler concerns). WOULD A SIMPLE POWER COMPACT FLOURESCENT UPGRADE BE ENOUGH? Can you recomend the best option The tank is only 20" deep (24" long)? THANKS

Answer 1

If your tank is 20" deep, it's not a standard 20 gallon - this should be 16 inches.

You're correct that the problem is your lighting. I would suggest using a double tube compact fluorescent. I use a Coralife on my 29 gallon with a 65W 10,000K tube and a 55W 03 actinic tube. Each tube is on a separate switch (and timer) so I can give a dawn-day-dusk-night photoperiod. A T-5 lighting system would also be compatible.

If you do have an odd-sized tank where the depth is 20 inches, you might do better with a metal halide, as these penetrate deeper into a tank.