I keep buying water heaters for my turtle's tank and they keep dying out very quickly. Some work perfectly for a while and then suddenly die out within weeks, and others are trash from the start and heat the water halfway to the temperature I set. I feel so bad for my poor turtle because he'll be comfortable for a few weeks/months and then suddenly cold until I can find another heater. I keep changing the wattage because some people suggest getting a heater a little higher than you need so it doesn't have to work as hard, and others suggest getting the lowest wattage you can that fits your tank. I'd really like to avoid buying several low wattage heaters due to limited space, but if that's what it takes, I'd still like to know of dependable brands. There must be some aquarium heater brands that work well and last more than a few months at most! Please let me know of any brands you'd recommend, preferably one with fair prices.
Also please let me know if I'm doing something wrong! I currently have a 55 gallon tank for my RES with 300W heater because I need a great increase in temp. from the external environment. I tried setting it in the mid 80's but it would only heat it to low 70's and then just stop working all together. I'm now setting it at 76 but it only worked slightly right after I set it, and then it stopped heating again. I've tried 200W and 250W, around the same temperatures, but they either do what my current heater is doing or they work very well and then die out.