Getting Connected: External Pump to Sump

[SkyReef]

Hello:

I have some questions about how to connect my PVC return line to my external pump.

I built a glass sump. It lies in the aquarium stand below the main tank. I drilled a hole at the bottom of the rear wall of the sump. I installed a bulkhead in that hole. I cemented a PVC elbow on the outside of the bulkhead. The elbow faces sideways, to direct the water out of the sump and immediately sideways. This sideways-elbow placement requires less space between the stand and the wall, as compared to a straight-out configuration.

I have an Iwaki MD-40RT external pump. I plan to simply connect a short PVC pipe from the sump-outlet elbow to a tru-union ball valve. I plan to connect the other side of the tru-union ball valve to another short PVC pipe.

That's where I get hazy. What connection fitting do I use to connect the inlet of the Iwaki MD-40RT to that short PVC pipe? I presume that I will use some form of an adapter: (a) one side of which has female treading on its inside to screw onto the male threading existing on the outside of the pump's inlet; and (b) the other side having a slip configuration, to be cemented to the short PVC piping.

Questions:

(1) Is that right?;

(2) Do I use teflon tape to secure the adapter to the pump inlet better, to help avoid water leaks?;

(3) Is the following method a good method (I read about this somewhere): Instead of using teflon tape to connect the pump plumbing, one should use silicone sealant instead. The theory is that the silicone seal that adheres the plumbing to the pump-inlet holds up much better over time than does a teflon-tape seal, to the continual vibrations of the pump. The proponent of this silicone-sealant method stated that it would not be hard for the user to manually disassemble the plumbing from the pump, at a later time, because the silicone sealant would permit such a manual separation of the assembly. Is this true?;

(4) What advice to you have?; and

(5) Which method is the best to connect my PVC elbow to the Iwaki pump?

Thanks for your wisdom.

[TellyFish]

Hello!

I would assume you are correct and your pump will require 2 "male adapter" fittings. One for the inlet and one for the outlet.

As for using the nylon tape, I prefer the thread sealant for critical fittings. I use the "Spears Blue 75" thread sealant. You can separate those pieces later, no problem. Sounds to me like you have a good understanding after all

[Islander84]

use the heavy duty pvc cement on any slip fittings rain and shine will work if pipe is wet but heavy will withhold pressure better. and for threaded they also make a heavy duty teflon tape but i dont think it will be necessary if it were a pipe that was under tremendous pressure with no release for long periods of time then i would recommend it but you should be fine and yes there are pvc fittings that attach to the bulkhead ftg you can get at any hardware store lowes home depot ace....make sure your pipe is schedule 40 not 20