I have a 29 gallon freshwater tank that I am currently doing a fishless cycle. This tank will be a community planted tank. I am struggling with the decision of a single flourescent fixture or twin flourescent fixture. My tank has a canopy and I am afraid that a twin fixture will overheat the tank. Have any of you had any experince with this? I am awaiting my plant shipment which will be in next week and I ordered all low light plants just in case. I have a 10 gallon planted tank with a single fixture and the plants are doing great.