$15 PVC Overflow

[keman]

Sure, but now the water level is high enough such that surface skimming isn't occuring.

There are five things I'm taking into consideration, which may not be priorities in the PVC setup outlined here.

1. Self-Restarting
2. Surface skimming
3. Sump capacity impact
4. Sufficient flow
5. Height adjustability

#1 should self-restart after a power failure, #4 Should not come at the expense of water height such that #2 doesn't happen and worse, your sump overflows by the time it stops because the process was so far backed up during normal operation it drains for 15 minutes and your tank drops 3" with water all over your floor. #5 of course is just nice to have.

My PVC design implemented slip-fit tubes at the intakes such that the water level was height adjustable. But.. if those joints ever leaked during a power failure, my tank would drop 6" before the leak would halt. The risk was simply too great for too little.

 

[Bluecircle]

Suppose A + B = C. If I want to increase the flow, What should I do? Increase A, B or C ????

 

[richard55]

I would think A. This is where the tank water will attempt to equalize. I hope this is not the finished product or that you will put in a siphon break. The way it looks now you will be pulling a LOT of water during a power outage.

 

[Herbert T. Kornfeld]

Increase A, but the intake level, lets say point D (the height of the syphon's intake inside the tank) must be below the bottom of A.

 

[Bluecircle]

If I cut the red part so the length of A will increase, does it help to increase the flow?

 

[pvtschultz]

Yeah, it will create more of a differencial pressure, increasing the siphon and flow to a point.

I think that one very good idea for these siphons (and what I am building now) it to take a length of 6" PVC pipe, rip it in half lengthwise, paint it black, and silicone it to the back of the tank to use as the skimmer and then leave it as Bluecircle has it. My idea anyways.

 

[dotMATRIX]

I always thought it was a2 + b2 = c2 ?!

I have no refugium or sump. At present I'm using only powerheads for flow, but I was given a working SCWD as a gift. Is there any problem with using this design (the original design) to feed a MAG5 and output to the SCWD back to the tank? The tank is only a 37g and I'm envisioning the pump being no lower than the bottom of the tank.

Your thoughts?

dot

 

[richard55]

Dotmatrix I think what your are discribing is a closed loop you will not need all the bells and wistles. just a feed from the tank and a return to the scwd. It will not need an overflow to stay primed as long as the pump is below the level of the water.

 

[orlenz]

Ok I see how this would work, But I think were getting off base, The sole pupose of an overflow is to skim the top of the water, not take water from below water level, you need to break the surface and take THAT water.

 

[richard55]

I think the purpose of an over flow is to get water from the tank to the sump without losing siphon and not draining the tank during a power outage. The one I was playing with did surface skimming also.

 

[orlenz]

if you just want to do that a J tube will work

 

[MikeSpS]

MORE POWER TO YOU MAN!!!

now lets talk about patent's. LOL

 

[dotMATRIX]

Surface skimming is a desire in this project. I was going to cut slits in the tube that sits in the tank and then cap the top of it to keep any snails out. The tank does have an HOB for added circulation and the occassional carbon bag, but it has no surface skimmer attached and will likely be gone after this setup anyway.

I'm hoping to use this setup to replace both the powerheads and the HOB.

dot

 

[durango_doug]

whether it skims the water or not, I think bluecircle's design is bad news. unless he has a really huge sump, there is just too much water that will flow from the tank to the sump if he does this. not to mention that it will be very difficult to control the water level in the tank with this design.

 

[durango_doug]

I meant too much water flow in a power outage

 

[Davidm]

If I use a 1 inch pipe would a returnpump that pumps 500g/h be to mutch. Or should I go with two 1inch pipes.

 

[GoldStripe]

that size pump should be fine with 1" plumbing. I think a 1" drain can handle around 600 GPH

 

[ckoral]

How in the heck can you accurately calculate the flowrate with all those elbows? I could come up with something like this myself but to get the flowrate right would be a challange.

 

[GoldStripe]

I'm sure there's a formula for it somewhere. The RC calculator here is good too. But I think it's basically a ball park figure because every setup is different.

 

[kbmdale]

you guys are making it to complicated. I made a pvc overflow with surface skimmers out of 3/4 and a 700 gph pump matched up without any tinkering at all....


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