I use flex watt and couldnt be happier with the results. When i first started i couldnt afford the racks, flexwatt, and proper rheostat. so i comprimised and bought the racks and flexwatt. I got the flexwatt from reptilebasics.com and for a rheostat i went to home depot and bought a 300 watt dimmer for a table lamp. you plug in your flexwatt to it and it plugs into the wall and has a slide on it to adjust the amount of power to your flexwatt. now it isnt ideal but for $13 you cant complain to much. Also it isnt self regulating so you need to monitor your temps with a gun and adjust it manually. I put a line on it for daytime and another for night time. I have since then upgraded but its a great way to save a little money for a couple months.