New setup for Sump - Need advice on return pump

[fishgate]

Well, I got a pretty good deal on a sump and overflow. Eshopps RS-100 sump and Eshopps PF-300 overflow for $110. They are both like new only used 3 months. So the pump I think will work is the Maxijet 1100 (294 gph/5.7 ft). My sump will be underneath the tank with about a 4 foot height.

Also just to confirm, my overflow should be able to outflow the return pump right? So at 300gph down and the return is 294gph should be fine? Will I need to throttle back the pump? The pump says adjustable flow so I assume this means I can throttle it back as needed.

And even though I will makes sure my sump can hold the water in the event of a power outage that will flow back into the sump, should I get a check valve for the return flow?

For the return plumbing do I just get one of these with a flexible hose?

 

[Ron Reefman]

You don't want the drain to be flowing more water than your sump pump! You want it the other way around, the pump flowing more gph than your drain can deliver. Then get a bigger pump and install a ball or gate valve between the pump and the tank to control the flow back up. Problem solved. You have to have some adjustability in the system so you can adjust it and keep it matched. In your plan, what will you do if your dran slows down over time and you can't reduce the flow from the pump? You need some kind of control to adjust... a valve.

As for the 'siphon effect', I wouldn't install a checkvalve. You'll need a really good quality one that you can remove and clean regularly in order for it to work properly (PITA). Just do the anti-siphon holes properly and again you won't have any issues. I did anti-siphon hole big enough so I could thread in a john guest 90 degree elbow. So rather than the water pushing out the hole parallel to the water surface, I can adjust the 90 degree elbow to flow the water where ever I want it. I even have one that is deeper in the water so I could aim it up and create more water movement at the surface for better gas exchange.

Good luck.

 

[GhostRider58]

+1 on what Reefman said.

I have the same overflow and I run a Mag 7 as the return pump. I have a ball valve to regulate the flow from the pump back to the DT. Works great.

And as Reefman said, do not put any restrictions in the overflow plumbing, a snail could spell disaster. You will probably want to build a Hofer Gurgle Buster or the overflow noise (like a toilet flushing) will drive you mad! Search the forum for Hofer Gurgle Buster. It is really easy to make and only costs a few dollars and quiets it down great once you get it adjusted correctly. Good luck.

 

[fishgate]

Thanks!

So get a bigger pump and lower the rate to balance it. And balancing will be the goal. But doesn't ultimately the flow through the overflow need to be slightly greater than the flow back to the tank? If the flow back to the tank was greater you'd eventually run your sump dry and/or overflow the tank right?. If your overflow is greater it just reduces your tank volume down to the level of the bottom of the overflow.

Also this is not a drilled tank, it uses a HOB overflow. So I need to make sure my sump can handle the volume in case of pump and anti-siphon failure. And I need to make sure my tank can handle the sump volume in the case of overflow siphon failure.

 

[fishgate]

You mean the MD7? That is the one I was going to get after reading the responses.

Model Shut off (ft) Maxgph Inlet/Outlet Watts per hour
MD5 10.5 500 1/2" 49
MD7 11.65 700 1/2" 60
MD9.5 12.85 950 3/4" 93
MD12 13.5 1200 3/4" 110
MD18 16.85 1800 3/4" 145

 

[sirreal63]

You don't want the drain to be flowing more water than your sump pump! You want it the other way around, the pump flowing more gph than your drain can deliver.

Let's clean this up a little. This is a U-Tube style overflow, it will only flow what is pumped up to the display, at the same rate, up until the point it is maxed out. It will not flow more than it is being fed. It can however, be fed more than it can flow to the sump.

OP, the MJ1200 would not be a good choice, because of the 4' of head pressure the pump will have to overcome. What has been said about getting a pump that pumps more and using a valve to adjust the flow is correct. The closer you get to the max the overflow, the noisier it will be. Ideally you want enough going to the overflow to let any micro bubbles that collect to flow through the tube without getting stuck at the top. You will have to adjust the flow from the sump to find the spot where it functions correctly and does not begin to flush. Look at pumps in the 500 gph range and plan the plumbing with a valve to adjust the flow. The excess flow can either be wasted or used to run reactors or used for additional flow in the sump area.