Review on Eheim CompactON Aquarium Pump 2100 by Denise Davis

I have the next larger pump in the same series (3000 not 2100). They are physically identical in size and inlet and outlet pipe size (both inlet and outlet 3/4" on both models. The only difference are the markings and the motor inside. Here are some stats: 3000 inlet 3/4" and Outlet Size 3/4" or 1" Minimum Maximum Flow Regulated GPH 476-793 W/H/D 4.1, 3.1, 2.9"2100 Inlet 3/4" Outlet Size 3/4" " or 1" Min Max Flow Regulated GPH 370-555 Size Width/Height/Depth 4.1, 3.1, 2.9" 1000 5/8" Inlet Outlet 5/8" or 3/ 4" min max flow adjustable gph 106-260 size width/height/depth 1.9, 3.1, 2.9" 600 (without inlet pipe for hose connection, outlet 1/2" min/max gph adjustment 66-159 Size Width/Height/Depth 1.5, 2.8, 2.4" 300 (1/2" outlet). End of exhaust pipe at 2100 or 3000 it will be 1" if not cut then 3 /4". end up being 3 /4", if not cut it is 5/8". 600 or 300 (1/2" drain and no choice). All have 6ft + 4" Power Core.dMine running ft now for 3 years 24/7 with no problems. Almost all (perhaps all) Eheim heads and pumps have used the same suction cups for many years, which Revain sells separately, model number 7271100. However, these CompactON pumps use a different suction cup (the suction cup itself is threaded on the back and screwed into the pump body, Eheim parts 7475518 for the 300 and 600 models. 7475538 for the 1000 models. 7475548 for the 2100 and 3000 models. All Ehiem Compact+ pumps and most of their heaters use suction cups #7271100 (they are unthreaded) .I believe they are interchangeable.Just clean them with water and paper towels or plastic utensils.Cleaning after applying 100% pure petroleum jelly (no additives) run your fingers over the cups, this will take some time (every 3 minutes), but after that wow the cups are like new i do this every year they are 100% fully submersible you can throw anything in a water tank and it's there all the time leave to work. But they are NOT suitable for use out of the water. Of course, the top of these pumps is when installed as a power head (with suction cups inside). tank wall) can be out of the water or in the water. There is a waterline body on the power head. This line must not be fallen below, otherwise the pump will overheat. Although it is submersible, it is NOT unsinkable except at the very top. You CANNOT use this tank water pump when two hoses (inlet and outlet) are connected and go into the tank. Five stars all the way!