Need some plumbing problem solving... BEAN?

[Tswifty]

Hey all,

I'm primarily looking for BeanAnimal, but any suggestions would help. Anyway, I just finished plumbing a friend of mine's nano tank tonight, and ran into an issue. To save space I decided to only use 2 of the 3 standpipes in Bean's method. The siphon and open channel line, and both are constructed out of 3/4" PVC. Well with everything in place, I fired up the pump, and the siphon will not kick in. The tank would overflow if I left it on long enough.

Now here's the kicker...

If I take the cap off of the siphon standpipe, and turn on the pump so it is running as a "drain" for a minute. THEN screw the cap back on... the siphon immediately kicks in, as I'm screwing the cap down.

This wouldn't be that big of a deal... except... if the power goes out, I'm back at square 1 and the siphon won't kick in again. So if the power would happen to go out when they are away from the house, then kick back on... there could be a big, BIG problem... as the tank would overflow.

Suggestions???

Here are some pictures:

 

[jdieck]

Drilling a small hole in the cap might be the solution.

 

[ironwill723]

From reading through bean's thread awhile back, it seemed to me that the emergency drain was needed to allow the siphon pipe to initially start up without overflowing the tank. From what I understand in the first few seconds/minutes after power has started up again the siphon needs so much water pressure going down before it begins. The emergency drain serves as the overflow until this happens. Could be totally wrong though.

 

[SeaWeed89]

OT to the OP but i belive bean is no longer with us on RC

 

[bnmir]

Well, I went with a 2 hole version of beans, and have been running that way for several months. I had to do some tuning initially to get comfortable with everything.
Sounds like you have too much backpressure for the siphon to start. The hole could be too close to the surface (not enough water pressure to start the siphon).
The siphon exit could be too far underwater in the sump. drilling a small hole in the line in the sump just below the waterline could help. The less air volume in the siphon line, the better. All that air has to get pushed out by the water pressure in the overflow.
So one option is to ditch the external T with cap, and go with a 90 degree elbow instead.

 

[raynist]

<a href=showthread.php?s=&postid=15287059#post15287059 target=_blank>Originally posted</a> by SeaWeed89
OT to the OP but i belive bean is no longer with us on RC

That is correct.

 

[Tswifty]

<a href=showthread.php?s=&postid=15287059#post15287059 target=_blank>Originally posted</a> by SeaWeed89
OT to the OP but i belive bean is no longer with us on RC

<a href=showthread.php?s=&postid=15287563#post15287563 target=_blank>Originally posted</a> by raynist
That is correct.

Seriously... again???

That's got to be a first. Win Thread of the Month, then get banned shortly after. I know a lot of people use his system, it's a shame he isn't around to continue to guide others... as well as help out in situations exactly like the one I am having.

 

[Tswifty]

Thanks for the responses guys. I have a few ideas that I plan on trying out later today.