Running Ehiem Return Pump out of water

[dlux5life]

Hi Guys-

I made the mistake of poorly designing my sump when I built it. I have a 90 gal SPS tank and a 30 long underneath with two sections, a large refugium and a return section that holds my return pump and skimmer. The ATO is also there to keep the water column fairly consistant. I am going to completely redo the sump when i first can, but cannot get the sump tank out with out draining the display tank.

I bought a new Ehiem compact pump that can run out of water which will give me more room in my return section and should prevent the micro bubbles that I am getting with it at this time. I could hang it over the edge of the tank wall with a tube drawing the water up from the return section.

Is there any disadvantage to running a pump like this long term?

I can fit it so the pump is submerged, but only where the water overflows from the refugium section. The increased output from the pump creates a lot of flow / bubbles which the return pump puts right back up to the display tank. If I can hang the pump, I can draw the water from an area in the return section where there are no bubbles.

These awesful diagrams may help out:

The way it is now:

They way I was thinking of doing it:

 

[dannyp02908]

The Eheim pump is capable of being run externally. I have one on my CA reactor for recirculation. The problem with your diagram is that the eheim pump will not be capable of drawing water upwards. It has to be have the intake flooded.

 

[Turbosnail]

+1 the eheim pump is not self priming. Can you get a pick of your sump setup so we can get a better idea of what you are working with?

 

[dlux5life]

Would it work if I were to hang the pump low enough so that when power goes out, the water level raises high enough to cover the intake of the pump?

I have loc line for my return and can adjust the levels to a point where the siphon will break a little later to allow the water level to raise to the correct point. There is a good 10 gallons of play that I have in the sump above where the top of the pump would be so I am not concerned about an overflow.

IE:

 

[dannyp02908]

Not sure. Try it in a bucket. My guess is if it does, won't be that great. Any reason you are adamnt on having it set like the rather than just placing it where it should go?

 

[JohnK]

That might work, but I wouldn't want to have to count on it continuing to work.

It is possible to have a pump next to the sump, with the inlet being an upsidown U of PVC that goes up and over the sump wall. This way the pump has to be manually primed at first, but once primed will stay primed even in the case of a power outage. That way the pump would still have to be sitting below the low water line in the sump, but the upsidown U will hold the prime.

 

[dannyp02908]

John - tried that with my iwaki before I drilled my sump. It never held the prime.

 

[dlux5life]

It not so much that I am adiment that i need to have it this way. I'd rather have it submerged under water, but the area that I have is roughly 1 square foot. In that area i need to fit my return pump, ATO sensor, maxi jet 1200 for carbon and gfo reactors and my skimmer (SRO SSS 1000).

I'll try and take some pictures of my sump tonight and get thos posted online. The hope is that I will be moveing to a new place with in a year or so. With the move will come a new, better designed sump.

Thanks for the input guys.

 

[JohnK]

John - tried that with my iwaki before I drilled my sump. It never held the prime.

There was probably a problem with how the pipe was arranged, or the sump design was allowing it to suck up air bubbles enough to break the prime. I ran an iwaki like that for several yrs and it never lost prime.

 

[dannyp02908]

Why is your skimmer in your return section. skimmers require a constant water level. i know you have an ato as you stated but i would still have the skimmer in a section other than the return. My sump has a small fuge on the side, that overflows into my drain section which houses my skimmer. the drain section then goes through bubble trap to return section. in my return section, i only have ATO sensor. i have a very small return section. Granted that my pump is externally plumbed. You could plumb your eheim externally.

As for all the reactors, i tee'd them off of my return.

 

[mchartier]

The skimmer in the return section is reliant on the ATO. My sump has no baffles, but my ATO is the Spectrapure UPLC thank can be set from a .1" to 4" level change and I have had no issues with my skimmer. If your just using a standard float switch then yes there maybe to much of a change in the level to have a consistent skim.

 

[dlux5life]

This is a standard float switch and there is too much fluctuation for the skimmer to work correctly. I dont see myself being able to re-do my sump while under my tank. I can't get the sump out with out taking the dt off. I'd like to cut the refugium system down by about half, then have it flow to the skimmer section and then through a bubble trap to a very small return section with the ATO. I am confident that I could empty the sump while under the tank, but getting a proper seal and making the bubble trap would prove to be very challanging.

 

[dannyp02908]

Any reason you can't just put the skimmer in the fuge section? I am sure you drain into the fuge. Then let that all flow into the return? Is your eheim capable of being a return as well as running your reactors. If so, teeing your return is easy.

 

[dlux5life]

I could try putting the skimmer in the fuge, but with the water level being as high as it is in the fuge section, i will need to build a stand for it to sit on. The SRO SSS 1000 needs about 7.5" of water to run best. My fear is that when the skimmer is on a stand, it will not fit under the tank. If it does, that is the solution to the problem right there. I'll just need to figure out a way to keep the caulerpa from breaking off into the skimmer pump. That won't be tough.

The eheim is capable of running the reactors, but I am using vinyl tubing for my return. T'ing would be difficult. I'd have plenty of room to keep the maxijet for the reactors if I can put the skimmer into the fuge.

I'll do the math tonight. Not quite sure how high the water level is in the fuge.