Heating and cooling. The temperature and more so the stability of it is obviously and important factor in a happy healthy fish tank. Just like us your watery friends will feel uncomfortable, if they are too cold or to warm. Everything you need to keep the temperature at it’s optimum is here. We have fish tank heaters with thermostats, fish tank heaters that need a separate temperate controller. Fish tank chillers or fish tank coolers and fans to reduce high temperatures especially beneficial for reef aquariums.