Siphon Overflow?

[The Ultimate DanK]

A friend of mine is setting up a sump and he said that he is going to use pvc to set up a siphon-overflow, then offered to do the same for me. How exactly does a siphon overflow work and is it something I would want to have if I'm wanting to run a sump/refugium?

[Daemonfly]

Proper siphon overflow - http://www.csd.net/~cgadd/aqua/overflow.htm

[FateX9]

can it work with pvc yes but i like to see if any air bubbles are getting formed in the tube because if that occurs then the flow decreases, and if you have it so that your overflow and pump matches, then ptentially its gunna overflow and i hate overflowing

the constant sound of drip drip drip

[EtOH_is_good]

that's a good link daemonfly

[rbja]

mine is just like that and it works grate. every now a then i get a little bubble .

[Matty1124]

i did one with pvc... it sucked big time if you are going to do it that way use 45degrees pieces and not 90s

 

i made a crazy one out of pvc but its kind of big... but its fail safe... let me see if i can find a link

[The Ultimate DanK]

Yeah, he said that an overflow box would not really be needed and that it could be done with just pvc. I was under the impression that you needed an overflow box for it to work properly.

[duderubble]

Yeah, he said that an overflow box would not really be needed and that it could be done with just pvc. I was under the impression that you needed an overflow box for it to work properly.

 

I tried one with PVC and could not keep air out of it, reducing flow badly. After 2 days I went and bought 2 specimen boxes and a bulkhead and DIYed a proper pair of boxes for less than $10. I used a pair of uptake tubes from unused HOB filters as the overflow. This gives the added security of having two paths if one would get bubbles, which never happens.

 

Someday I'll post pics of it.

[Daemonfly]

There's a few pvc-pipe only designs out there, but they're pretty rare. I tried making one for my 2.5g and it worked, but the flow was too slow.

[duderubble]

There's a few pvc-pipe only designs out there, but they're pretty rare. I tried making one for my 2.5g and it worked, but the flow was too slow.

 

The theory seems to be sound with the PVC ones but it just didn't work for me. As I reflected on why my PVC one could not keep air out, I decide there was just too much churn in the pipe causing bubbles to get sucked up and the 90 degree elbows trapped that air at the highest spot. With a box the flow is smoother, no churn, no bubbles and it skims alot better too. And in the end was cheeper than the pvc!

 

If you design the overflow box, the sump and the return properly there is no room for catastrophe, you simply can't overflow or overfill no matter what stops working or gets clogged. It would take at least two simultaneous problems to cause an overflow in either sump or tank. Even in the case of a pipe break with a nano the most you could lose is a gallon or so of water.

[yankeereefer]

Here's a link to the PVC version - I built one out of 3/4" - It's big, but it works

 

http://www.3reef.com/forums/i-made/nice-ch...flow-29396.html

 

YR

[duderubble]

Here's a link to the PVC version - I built one out of 3/4" - It's big, but it works

 

http://www.3reef.com/forums/i-made/nice-ch...flow-29396.html

 

YR

 

That's totally different than the one I built and it looks like it would work fine. But also wouldn't be any cheaper than the one I ended up with.