prop tank plumbing

[JohnNLuc]

Try to follow me on this one. I just finished constructing my prop tank that will soon be going under my main I have discussed several methods of moving water through it and came up with this as the best idea (since pumping water in both directions is out of the question) I constructed a basic u tube of pvc that will hang on the back of my overflow on my main. (pictures below) My main overflow leads down into a sump with live rock rubble im thinking of putting this in the back compartment of the overflow having it syphon water down into the prop tank and moving water back out of the prop tank via pump back into the return compantment of my sump this would all be controlled by ball valves to make sure the water coming into the tank is equal to the water being taken out the question is with this pvc u tube i made whats the easiest wat to start the syphon down into the prop tank?

 

[JohnNLuc]

Anyone?

 

[JohnNLuc]

Grrr come on people noone has any idea on how to start it? Im waiting on you guys to give me an idea on how to do it so I can get it started up and running.

 

[ellisz]

Sorry, can't help much on this one. Gravity feed is the easiest method and what I use for my prop tank. I guess you can't do it that way though...

bump

 

[RLG2182]

Have no idea how to start that thing... but I know that it's almost impossible to match the speed of pumps & water flow through valves, having tried so myself. If I were you, I would merely put a pump in your main sump in a compartment, and have it pump directly into your prop tank. If your prop tank is higher than your sump, all you need to do is drill a bulkhead fitting into the prop tank and have it drain into your main sump. That way, there's no extra valves or whatever to worry you. That pump going into the prop tank can only pump water into the prop tank as fast as it can drain it... problem solved. Thoughts?

 

[JohnNLuc]

The sump and the prop tank are on the same level surface and I cannot raise either. That is why i said gravity would feed the water down and the pump would push it back into the main sump. I just dont know with that PVC tube how to get water flowing through it down into the prop tank.

 

[RLG2182]

It's just that you have a bigger problem than getting that pvc tube going. I guarantee you that you will run into either of two problems:

1) You will overflow your prop tank because the pump isn't going fast enough, causing your tank to drain all over the place until it reaches the bottom of the pvc tube to let air into the system, or
2) You will burn up your pump because it's pumping too fast and you're draining your prop tank too fast.

I thought I could do something like this too, but trust me, this kind of setup is just asking for trouble. If you do want to try it for yourself, I would start the syphon by installing a "T" joint with a threaded end on the T, and a male threaded cap ready to go. Put the T on the way down to the prop tank. Start to suck the air out while plugging up the exit hole of the pvc tube with your finger (inside the prop tank), and when it starts, quickly plug up the open end of the T by screwing in that cap. Just make sure to have a towel handy cuz it'll spray all over the place till you get that cap on. If you put a ball valve above where the T is, you can also shut off the flow before the water runs all the way down, and after the cap is on, you can open the ball valve the rest of the way.

~~Rob