Thanks for the info nasher8860. Internal pumps are bummers IMO. I'm hoping to turn mine all into external. Now that I have my aquascaping done, I'm going to start working on a closed loop with an external pump and also, convert my return pump from my sump to external also. I'll let you know also how my temp runs before and after. Mine us to sit at 88-90!(LOL) until I removed the glass on the top of my tank and removed a troublesome JBJ pump thant got my temp to about 84. Good luck....