Hang on overflow

I want to build a sump for my 55gal tank, but it does not have an overflow already built in. Any opinions about hang on overflow boxes? I've heard CPR isn't very reliable and that I should go with an eshopp one. Also, any ideas about how to set up the overflow so that it an air pocket doesn't form over time and break the siphon? Thanks for the help.

 

You can get a tom's aqua lifter and put the intake in the u-tube so it pulls air bubbles out.

 

I've read and seen a few DIY mods where u can run an aqualifter pump attached to the u-tube to ensure constant siphon. Personnally I have no experience other than the research I googled. I too am just now finishing up on the rest of my equipment needs before I begin. I'll be following along with this thread.

 

The cpr overflows has the 3/16 tube in the top to hook an aqua lift pump to. That is a plus because if power fells it can start its own siphon back once water reaches a certain level in the tank. I watched the CPR vid, on fosterand smith and they said Tom's aqaua lifter or a powerhead, one thats has the air siphon on it. The Eshopp ones i have seen doesnt have the siphon on the tubes, once it is broken it doesnt start back that i know of. I did a DIY suction type, just a shepards hook with a "T" pipe and caps. I drilled and put 3/16 tube in top and ran it to a powerhead i all ready had. It started itself and has worked great. There is a guy with CPR type for sell for 40 bucks on here also.

 

With a U Tube overflow, you don't need an aqualifter or any nonsense like that; that's the chief advantage of the U Tube to begin with - no pump to worry about! You just need enough flow through the tube. The sheer velocity of the water movement will keep bubbles from accumulating in the tube if you set it up properly. If you need less of a flow rate than the overflow box can handle, you can just downgrade the U Tube to a smaller size; that way, you get a higher velocity through the tube.

 

I use an overflow box that came with my tank that I bought used and never never had a problem with it. No need for a pump

 

I have the Eshopps PF-300. It has been running on my 55G for almost a year now and has not given me a single problem, yet. It is rated at 300gph in which I use a Mag 5 for a return pump. My return piping includes a recirc (to control flow rate), a union (for quick disassembly), a Y-splitter to split the return water between a tank long spray bar and some locline that just moves the surface water. I do have a ball valve on the locline side of the Y-splitter to control the differential pressure between the spray bar and locline outlet. So far everything is working out great!

I have had way too many power outages (somewhere around 15-20 times since early July). Most of the power loss happened during 12am-5am. I know this because it was scheduled by the local electric company. So far the Overflow box has held it's siphon while the tank drained to the lowest point.

The only downsides that I can think of the product is:

1. Starting the siphon thru the U-tube can be a PITA until you learn the right way to start it. I just use some plastic aquarium air line and stick it inside the U-tube in the exact middle. Place the U-tube back in the Overflow Box. Make sure that both chambers that the U-tube ends are in are full of water. Then, with all your capability, take the opposite end of the plastic air line and suck out the air from the U-tube as fast as possible. Both ends of the U-tube should have water rise to the center of the tube and start moving water from inside the tank to the Overflow Box that is hanging on the outside. Then just pull the air line out and presto!!!! All done!

2. The black sponge filter is great to use that is supplied with the box but is a nitrate and waste factory. It must be cleaned atleast once a week.

3. Last but not least, the box's GPH rate maxes out very easily. This can create a Toilet Flushing sound that can be very irritating. I solved this issue buy placing a plastic spoon on top of the 4" PVC tube that slips into the bulkhead fitting on the external box and then placing the Black Sponge filter back over the PVC tube and spoon. Make sure you use the smaller cylindrical Black Sponge filter to fill in the opening at the top of the Sponge sitting on the PVC tube. Cut to fit it flush.

Sorry to make this so long but I want to make sure that you know everything I know before you buy.

 

x2 good tip

 

I'll add to make sure the piece of airline is very long, like 10+ feet. That way, you can suck more before you get a mouthful of saltwater.

 

X3. I currently run both a CPR-90 with the aqualifter pump and the Eshopps PF-1000. I can honestly say that the CPR is just nonsense like blackraven stated. The need for a pump just because you have "the whole body of the weir" acting as a siphon is BS in my opinion. I also got carried away and let myself get influenced by other people. But when I put one next to the other, the U tube beats the weir at everything. Simplicity works better in this case.
I found with the Weir overflow, that the nipple on the top (where the aqualifter connects to in order to suck the air out) gets clogged very often and weird things start happening. As soon as you try to unclogg it and disconnect the little hose it looses siphon, of course. So you have to also shut down your return pump before you mess with the weir.

Only 2 times I almost overflowed my tank, and both of them were caused by the CPR-90 weir overflow.

So... this is how I'm running my tank now: I have the eshopps pf-1000 which can handle way more flow than what I need, but If I ever upgrade, I'll be covered. We all know that the amount of water that will pass through it is pre-determined by the rate your return pump is set to.
My CPR-90 is set up quite a bit higher than the eshopps overflow, with a little piece of tubing and a little air valve that I opened, sucked the air out and closed so in case my tank water reaches that level, due to an overflow of some sort this would act as a backup unit to try and keep the extra water volume out of my floor... nothing else than a backup.

- Mag.