While many hobbyists battle with high temperatures in their aquariums, low temperatures can be just as damaging. When the winter months hit, the water temperature can drop from it’s usual 76-80 degree range to one in the sixties. This may not seem like a big issue, especially since many fish and invertebrates are found in waters that are cooler than what our reef tanks normally run, but most animals just won’t be able to cope. Corals can bleach, clams can close up, and fish can disappear into the rocks. Because of this, heaters are a must in virtually every climate, as weather is virtually never constant anywhere.