Pump Output Designations

ev1016 · 04/01/2008, 03:29 PM

I have gotten good reccommendations about iwaki pumps. Marine Depot has the following description of the 2 basic pump designations:

RLT pumps are for pressure applications. RLXT pumps are for circulation and wet/dry return.

I presume I would want an RLXT for a sump return, correct? I am not sure what they mean by pressure applications. Can anyone elaborate?

lark · 04/01/2008, 04:11 PM

The most common situation in which you'd want the rlt is if you're running through a cannister filter, or some other device that creates back pressure. Several elbows, or forcing the water through an opening smaller than the pump's output (e.g., if you run through a chiller on the way back to your return that has inputs smaller than the diameter of your output) can also cause back pressure.

If you've got a relatively straight shot back up to the aquarium from your sump, the XT models should be fine.

If in doubt, the rlt is the better choice, since it also can run in non-pressure situations, but the same is not vice versa with the xt. I went with an rlt -- I bought one size bigger and got the pressure rated model. Figure it gives me more flexibility. Great pump. I've had it for a long long time.

04/01/2008, 03:29 PM	#1
ev1016 Registered Member Join Date: Mar 2008 Location: Chicago Suburbs Posts: 86	Pump Output Designations I have gotten good reccommendations about iwaki pumps. Marine Depot has the following description of the 2 basic pump designations: RLT pumps are for pressure applications. RLXT pumps are for circulation and wet/dry return. I presume I would want an RLXT for a sump return, correct? I am not sure what they mean by pressure applications. Can anyone elaborate?

04/01/2008, 04:11 PM	#2
lark Registered Member Join Date: Jul 2001 Location: Phoenix, AZ Posts: 535	The most common situation in which you'd want the rlt is if you're running through a cannister filter, or some other device that creates back pressure. Several elbows, or forcing the water through an opening smaller than the pump's output (e.g., if you run through a chiller on the way back to your return that has inputs smaller than the diameter of your output) can also cause back pressure. If you've got a relatively straight shot back up to the aquarium from your sump, the XT models should be fine. If in doubt, the rlt is the better choice, since it also can run in non-pressure situations, but the same is not vice versa with the xt. I went with an rlt -- I bought one size bigger and got the pressure rated model. Figure it gives me more flexibility. Great pump. I've had it for a long long time.