Hi... In my 240 i have one CK and a LMB along with pleco and 2 koi... The tank is heated by a 120w heater cuz im to cheap to get the right heater.... The heater keeps the tank around 75... which the CK is really happy. My question is. can i put in say aro/pbass/oscars or any other Warm water fish that ned to be around 80? Cuz i was told the ck needed 80 but his been around at 75 and lower and loves the tank. thanks oh and what are some low heated monster fish?