I have a sump in my 75 gal and I am putting one together for my new 40 gal . I would like to know if , you use a heater controller , do you put the probe in the tank or the sump . Can it go in the sump ? I use them and I have the probes in the tank . I would like to put them in the sumps , less equipment in tank . Also , can you have the input from a canister filter in the sump and the return in the tank ? Not to drive the sump , I have pumps for that ,but just to get the canister intake out of the tank . TIA for any advice .