I have a 55G tank. Planted. Stock: (temperatures in Celcius) (17-28) (21-26) (22-27) (18-26) ( to come) (21-26) Given the above. Was I correct to drop my heaters from 26 to 24 to be safe? They haven't died, but I just want to make sure that setting the temperature in the middle is better than warmer water near their 'maximum'.