| Gina I have a Derasa clam in a 20 gallon tank under a single 175 watt 10K MH....this thing is growing like a weed. I havent had it a full six months yet and its added at least 1 1/4 inches to the shell in new growth. I dont think that clams do bad under more light as long as they are acclimated. Barry told me via phoe conversation that his clams are under 150 HQI lamps in shallow custom made aquariums. For the record many people have caompared the 150 watt HQI to the 250 single ended/ mogul based bulbs due to the advanced reflector design which returns more of the available light back into the tank. You should be fine depending on the depth of the tank.
Nick |