Sump return question

I will be putting a sump together soon with an Eshopps pf-300 overflow, and a Mag 5 return pump. I've read many post and threads about setting up to prevent overflow should power go out. But unless I missed it, I could not find how to prevent overflow of the DT if the Eshopps overflow loses its siphon. If the U-tube stops working and the pump is still running, the entire sump will drain into the DT.

Should I be as as worried about this possibility as I am?

I purchased the overflow used, was missing foam tube. Is it necessary? Does the U-tube just hang loose?
My first sump.
Thanks.

 

For this particular disaster to strike, the overflow would have to lose siphon while the return pump continues to operate. While not impossible, it's pretty unlikely. If it does happen, the only flood to ensue would be from the contents of the sump. This is certainly the lesser of two evils when you consider a flood from the display tank's contents.

When the overflow loses its siphon, the return pump will pump all it can back to the DT. If you've done everything right, the first few gallons will be accomodated by the DT, as you should have at least an inch or two of space on top when the tank is running normally. After that, since the overflow isn't pulling down to the sump, the remaining water in the sump should be minimal. You'll have a wet floor, but you won't be filing an insurance claim--probably.

It's good that you're thinking about such possibilities. It shows you have a heads-up mentality. That'll take you far in this hobby.

And welcome to 3reef!!

 

Thanks ReefSparky.

What about the foam and the U-Tube? Is the foam important, and does the U_Tube just lay there loose?

 

You'll get differing opinions on the foam. I didn't run it when I used such an overflow, I placed my mechanical filtration elsewhere. The foam is prone to clogging and fast. Once the stuff that clogs it begins to decay--which is immediately--that foam is producing nitrates and becomes an enemy.

As for the U-Tube, it should be placed such that when power goes out, both ends remain submerged. There should be mini baffles in your overflow to achieve this. Pull the plug and see if it remains under water (doesn't lose its siphon). If this is the case, then you have it positioned correctly.

Good luck!

 

the best way to prevenet an overflow is to drill a small hole in the u return tube where it is underwater. when you loose electricity your overflow will continue to work untill the water level drops a little bit and no new water can enter the overflow. Once the water in your tank drops about an inch, the hole that was previously drilled in the U return tube will be out of water. This hole will break the suction and stop the return tube from draining back into your sump. This works very well, and you will only loose a few gallons from your tank which your sump should be able to handle easily.

 

Thanks, but that wasn't my question. I've read many posts about losing electricity.

My concern was about the possibility of the U-Tube losing siphon, and the pump continuing to operate.

 

This is also a concern of mine. I finally switched over to a sump. But the problem I have is one of the two U-Tubes keeps loosing siphon? Any ideas why?

 

Huh?!?! I think you wrote this wrong. The hole gets drilled in the return line just below the water level and not the U tube. Under no circumstances do you want the U tube to lose siphon.

The solution to this is proper adjustment of the height of your overflow in your tank. Simply lower the height of your overflow so your DT can handle the volume from your sump if your U-tube loses siphon. If you have a very large sump place your return pump on something so it is off the bottom. That way the water level will drop to the pump quicker and stop pumping because it will start sucking air.

The cause of siphon loss is the accumulation of air bubbles in the U-tubes. This usually means you need to increase the flow of your pump. With more flow the bubbles will be swept through the U-tube and not be allowed to accumulate. I recommend just eliminating one of your U tubes.

 

you might want to try and remove one of the u-tubes, this will increase the speed of the the flow preventing bubbles from building up, just make sure its still enough to keep up with the pump although if you are loosing siphon in one of the tubes i suspect one will keep up fine. also if you have the eshopps, i think any of the dual intakes use 2 of the smaller u-tube, you might want to try one of the bigger ones if one small one is not enough.

 

Alright, as always thanks a lot for the help.