DIY MAME-style PVC overflow

[vash028]

So if the power goes out the siphon is suppose to stop right ?

[neven]

Thank you for the well made renders, it helped a ton when i made my first overflow. One issue i ran into was the render shows the T at the same height as the bottom of the overflow loop, i found it had a hard time establishing a strong siphon until i added a longer section in between. Unfortunately it was all glued up by then

 

I managed to get the overflow to self siphon via venturi from the return with a very short nipple. Took me 26 attempts (yes i counted) and 2 tank overflows because my children distracted me >.< In the end i was able to get a consistent siphon that was able to restart very quickly with or without being primed.

 

I had to use a 4" piece of 5/16 ID tubing bridged between the two. I lengthened the top of my return so there would be less water turbulence. After many attempts i abandoned the cut end on the tubing and pushed in a barb coupling right to the hole. That alone wasn't enough, it still worked in reverse only. I did manage to get it to work with a small circle of vinyl tubing around the barb, but i sacrificed way too much flow and the siphon was weak, result, a very slow gradual tank overflow. So i had to get more creative. Due to being a fresh water planted tank junkie (i know wrong forum), i had a ton of dosing syringes from EI dosing. These all came with these rubber corks that resemble a step drill bit (for those tradesmen here)

 

ex.

 

I trimmed it down to fit in the 1/2" PVC, really had to hack it up so there was room for water to flow by at ease. I pushed it over the Barb (perfect fit) so the flat side would be on the opening. The result, strong flow thanks to the gradual smooth narrowing of the return, and a strong enough vacuum from the overflow that water was actually being sucked into the return through the 5/16 nipple (albeit slowly). Well within 30 seconds of power resuming, the siphon tube is filled with water and maintaining a decent suction, with only a little noise (from my understanding its normal with pvc).

 

I tested it a bit.

I added some debris around the overflow (probably more than accumulates in a week), water level didn't budge.

Plugged the overflow with my finger, when the water was almost over the top i let it drain, very quick recovery of water line.

Turn off the pump, let air back in the overflow, and it still resumed (did this several times)

 

I am quite satisfied with how it turned out, but i'll need to remade the overflow down the road so it wont have those couplings.

[neven]

heres what it looks like. Also to note, i replaced the kinked tubing

 

[tommer]

Im going to do one of these tonight. gotta go get the parts from lowes

[kveekx]

I was having a tough time finding all the parts at lowes and I was wondering if anyone could build one for me?