When it comes to selecting the best aquarium heater size there is no "per gallon" rule that works in all cases. More often than not the size of your heater will be determined by the wattage and quality of your heater. This means the cheapest, biggest heater may not be the best aquarium heater. I'm currently in the process of cycling my new 10 gallon tank. I bought an Aqueon Pro 50 watt heater for it but I'm not sure it's working correctly. I've followed the instructions given. I let it adjust in the water then turned it on and didn't move the temperature for a day, it was at 78. I'm doing a fishless cycle and read that bumping up the temperature will help bacteria grow faster, so I This is a review of the Aqueon heater that I use to heat my 20 gallon reef aquarium. This product is excellent and keeps the temperature very level. I recommend a larger heater for aquariums that The Aqueon QuietFlow 75 LED Pro Power Filter feature four stages of filtration-mechanical, chemical, biological and wet/dry-for the cleanest, clearest, healthiest water. LED light that flashes when the cartridge becomes clogged and needs to be replaced. I got an Aqueon Pro Heater for my 10 gallon. On the box it says that there will be a red light when starting up/heating. It is plugged in and I see no red light. Again, this is brand new, out of the box. Is it suppost to face vertically or something? Help. Aqueon Pro Heater is confusing me! So I ordered a brand new 100 watt aqueon pro heater from Amazon two days ago and it came in the mail yesterday. I followed the directions (acclimate the heater, plug in, moniter for 24 hours), but I am still dumbfounded as to what to do. Its manual says the Check out my stream at: www.twitch.tv/cfl_mike PSN: Cfl_Mike Check out www.americanaquariumproducts.com So heres a quick review of the Aqueon heater Save aqueon pro heater 250 to get e-mail alerts and updates on your eBay Feed. + Items in search results Aqueon Precision Calibrated Aquarium