I think I am going to hold on the chiller..I may get lucky enough by using two external pumps..and ample fans on the lighting that I will not require a chiller. But if it does turn out that I require a chiller, it will not be to difficult to impliment it into my current plumbing at that time. But here is another question I have....my return bulkhead returns require 3/4" pvc ( I would go to 1" bulkhead fittings, but the spray nozzles I am using only goes up to 3/4"), how much flow loss would I have if I did the entire plumbing with 3/4" vice 1" on all up to the return bulkhead fitting in which I would have to decrease to 3/4"?