There is ONLY one pump to both buy and use. I bought a **Japanese Iwaki 100r** 23 years ago it pumped right at 1900 plus.. gallons an hour 135 plus gallons per min. !. I run 265 gallons total on my system. 2 tanks a 90 and a 110 and a 100 gallon sump of sorts a 100 gallon horse trough lol. Heavy duty pumps these are and with a huge head height. It went bad on me right at 4 months ago now. I bought another one from BRS ( I shopped very extensively both new and USED 1st ) for $478 dollars free freight. I would use NO OTHER PUMP PERIOD ..! It lasted right at 23 years! 365 days a year, 24-7, for 23 years. That breaks down like this.. 24 hours a day, 7 days a week = 168 hours a week, 168 hours x 365 days a year = 61,320 hours in a year, 61,320 hours x 23 years = 1,410,360 TOTAL HOURS THIS PUMP HAS RUN NON - STOP... NOW you tell me is there a better pump out here..? Really tell me... no other pump will last this long ever! They have never changed anything on these pumps at all. I did talk to the factory direct no changes ever. Take this to the bank period... Oh and I got the dark gray replacement pump just like "I" had before, again bought the new one from BRS aquarium ** Japanese only.