Getting Connected: Sump to External Pump

[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 ( 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.

[Urchinhead]

1. Yes.

2. Yes.

3. No.

4. Add two ball valves so that you can remove the pump for maintenance without draining the sump or having the return line drain on you. One before the union connecting to the in side of the pump and one after the union connected to the out side. Additionally add a gate valve after the out ball valve or in place of it to control the amount of return flow you generate so you can better balance the drain line speed from the tank to the return speed of the pump. Add a gate and/or ball valve to the drain line too for the same reason.

5. Male/female threaded adapter with Teflon tape.

[Dizzle21]

i dont mean to thread hack, but what is the difference between a gate and ball valve? sorry thanks

[Urchinhead]

Ball has less granularity of control than a gate. In other words ball is harder to make small/precise adjustments to.

[SkyReef]

1. Yes.

2. Yes.

3. No.

4. Add two ball valves so that you can remove the pump for maintenance without draining the sump or having the return line drain on you. One before the union connecting to the in side of the pump and one after the union connected to the out side. Additionally add a gate valve after the out ball valve or in place of it to control the amount of return flow you generate so you can better balance the drain line speed from the tank to the return speed of the pump. Add a gate and/or ball valve to the drain line too for the same reason.

5. Male/female threaded adapter with Teflon tape.

 

Hi, Urchinhead:

 

Thanks for your quick, informative reply. So, if I follow you correctly then:

 

(1) Silicone Sealant Idea: Using silicone sealant, instead of teflon tape, on the threading of the inlet and outlet of the external pump is not an effective way to secure a leakproof connection at the pump, while also allowing for easy, future disassembly;

 

(2) Order of plumbing components from output of sump to inlet of external pump: Sump Glass Hole + Bulkhead Output+ PVC Elbow + Short PVC Pipe + TruUnion Ball Valve + Short PVC Pipe + Adapter + Teflon Taped Pump Input; and

 

(3) Order of plumbing components from output of pump: Teflon Taped Pump Outlet + Adapter + Short PVC Pipe + TruUnion Ball Valve + Short PVC Pipe + Gate Valve + PVC Pipes back to the tank?

 

Thanks for your help.