Hi, Im new to this forum thing ! I have a Juwel Rio 240 Tropical tank, it's been up and running for 9 months, all fish are healthy. The tank has 2 fluoroescent tubes in the canopy hood, I currently have them switching on and off via a timer. Ive heard that to help simulate the fishes natural environment ie the wild, that it would be better if the lighting reduced gradually, and came on gradually, by use of a rheostat. My question is whether it's possible to fit a rheostat to this aquarium ? Any advice would be appreciated.