diy overflow

Hey guys, following a guide which I believe was based off this one, I made a PVC overflow for my 140Gal today, planning to run a 3000lph (750gph) pump on it at around 2000lph (625gph) or so, need to get the figures on how it goes for siphoning but a mate has one the same size running at those figures so should be good.

Photos.







Inlets



Flexi joiner design.

Looks a little weird but because of where my tank is located, inbetween 2 walls, I can't plumb the entire thing with PVCbecause I have a fully enclosed cabinet and I'd need to move the tank, so I've opted to use 25mm flexible piping for the rest of the plumbing to the sump (have all this well planned out), where taps will be located for both the intake and return.

The design is perpendicular because it runs from the back corner of the tank where the actual in-tank pipe will be, forward so it has room, and then loops back around to the tube connector. Also have a male tap fitting on the top of the design for filling the tank up, my physics may be wrong, but if my tap on the overflow is turned to off, putting a hose into that and filling it will fill the tank (any comments on this? not 100% sure about it)

Haven't tested it yet as it's curing but should be good.

How does that intake work? I like that idea better than a U inside the tank. Let us know how it works.

Thanks.

acrosstic;1720244; said:

How does that intake work? I like that idea better than a U inside the tank. Let us know how it works.

Thanks.

Click to expand...

It's exactly the same general concept, 2" outer piping surrounding a 1" pipe that runs down close to the bottom of of the 'canister', it then flows up the 1" pipe, pushing air through the following sections thus creating the siphon force.



Diagram taken from http://www.jimweller.com/robs/PVC_Overflow.htm

the whole checkvalve thing is a fail... grrrrrrr... other than the dosing pump has anyone come up with something that works... i had mine attached to a powerhead i have no idea if it worked or not though because it only lasted like an hour.. i didnt like the extra current

I have made 2 of these and they work great when i help start them up. when i simulate a power outage the water level drops an inch below the overflow, when the pump restarts the water level quickly gets back to the overflow level but the drain does not start back up. plz help.

not yet confident to leave going while not at home incase i have a power failure.

I have the thread, all 64 pages

chesterthehero;1725351; said:

the whole checkvalve thing is a fail...

Click to expand...

You did something wrong.

swamptrout;1844359; said:

I have made 2 of these and they work great when i help start them up. when i simulate a power outage the water level drops an inch below the overflow, when the pump restarts the water level quickly gets back to the overflow level but the drain does not start back up. plz help.

not yet confident to leave going while not at home incase i have a power failure.

I have the thread, all 64 pages

Click to expand...

You also did something wrong. The water level can only drop to the level of the intake of the overflow. Simulate another power outage and see if the return from the pump is syphoning out water. If this is the case, drill a hole in it just below the water's surface.

As for not restarting, post a picture. Since you have all 66 pages, you should be able to figure out what you did wrong (you made some changes from the original just like everyone else).

Okay it only took me.. well you dun wanna know how long it took me
but this is MY level of understanding.. at this point.

/save to PC to restart animation or hit the F5 key on your keyboard.
flame on.

Has anybody figured out a shure fire way of siphoning off the bottom?

I tried the approach of teaching my fish to poop at the surface next to the overflow. Lets just say the results are less than splendid.

ar0wan;1845746; said:

Okay it only took me.. well you dun wanna know how long it took me
but this is MY level of understanding.. at this point.

/save to PC to restart animation or hit the F5 key on your keyboard.
flame on.

Click to expand...

Very nice!!! You rock!

Two changes though and it will be perfect. On the inside pipe, the down turned 90 is a modification that should be removed from the Overflow 101 diagram. It is very usefull in certain setups, but it doesn't need to be addressed right off. If it is to be considered, a hole should be added to the very top of that loop to act as an air relief/vacuum break. The system will not restart without this hole.

Second, after the system is first primed (adding water to the vent pipe) the remaining air must be sucked out using the check valve that is to be installed in the upper loop.

When you make these modifications, start a new thread called 'Overflow 101' or something like that. These current threads that we have are way too dissorganized and your new thread is what we need to replace them.