Full Siphon Possible?

fishgate

Active member
Can I somehow get a full siphon going on a single drain overflow like an Eshopps PF-800?

st-32886-PF800.jpg
 
What do you mean a "full siphon"? I have a single drain eshopps overflow on my tank that has ran flawlessly for over a year. You just need to make sure that your overflow can handle your return pump. I put a regulator on my return so that I can adjust it to make sure I get a strong siphon with no chance of air building up in the tube and stopping the siphon.
 
I mean a full siphon from the drain down to the sump. Can you get it to go full siphon and can the overflow's single tube supply that amount of water?
 
Theoretically, yes. Given the right size drain tube and some fine tuning its possible.

But given that there is no DRY backup, I would recommend against it. If its a new tank, just drill it and save yourself the trouble.
 
OK thanks. So I never fully understood the full siphon concept. Does the dry backup help to balance out the system so if your return is a little greater than your siphon the extra volume will trickle back to the sump via the backup?
 
I did this to my overflow box that looks about the same as yours.

The existing drain line has a gate valve on it before it gets to the sump to control how much flow I'll allow through it.

I used a hole saw and cut a hole on the side by the existing drain and put a bulkhead in there. That line goes straight to the sump - no valve.

That new bulkhead/valve acts as the dry backup / overflow line. Adjust the main drain gate valve so that the water slightly touches the overflow drain and all seems to work pretty well...

And it's soooo quiet now... no gurgling or venting noises.
 
The DRY backup (and it really needs to stay dry all the time) is there in case the siphon has something either partially or full obstruct the siphon. When that happens (not IF, WHEN), the dry emergency is able to handle all the flow being blocked. Also, it is intended to be noisy so that you know something is wrong and can investigate and resolve the problem. And the reason it needs to have no water in it is to prevent stuff from growing in the emergency line.
 
I did this to my overflow box that looks about the same as yours.

The existing drain line has a gate valve on it before it gets to the sump to control how much flow I'll allow through it.

I used a hole saw and cut a hole on the side by the existing drain and put a bulkhead in there. That line goes straight to the sump - no valve.

That new bulkhead/valve acts as the dry backup / overflow line. Adjust the main drain gate valve so that the water slightly touches the overflow drain and all seems to work pretty well...

And it's soooo quiet now... no gurgling or venting noises.

This sounds like a great idea - would you post a picture of it?

Thanks!

I just got a Jebao DC-6000 return pump and it seems a waste to not run a full siphon since it should be able to handle that volume.

I should drill but I want to try this first.
 
Sorry it took so long to get some pics, fishgate. I hope these will show up... trying it from Flickr.

This is the side of the overflow box that I drilled the hole for the bulkhead.


With flash...


From the top... I use a flat strainer on the emergency line to save space, and a cone-shaped strainer on the main siphon drain line (this one isn't visible).


Hope that helps...
 
Unfortunately I did'nt do enough research before buying and setting up my DT. I did not get a drilled tank. I have a lifereef overflow wich came very highly recommended. I've had it running for close to a year and has never lost siphon no matter how many times I've turned the system off and on.
 
Lifereef overflow here too... much more recommended over the ones that require a pump to maintain the siphon.

I've used it for over 10 years and it's never failed me. Clean the U-tube every couple months with a pipe cleaner and it's good to go. Keep some airline tubing to restart the siphon after cleaning it :)

Having said that, I was tired of the constant gurlging, even with an adjusted standpipe. That's why I finally decided to go with the setup in my pictures above. Also, much less bubbles in the sump now!
 
OK thanks. So I never fully understood the full siphon concept. Does the dry backup help to balance out the system so if your return is a little greater than your siphon the extra volume will trickle back to the sump via the backup?

Also, think about it this way, by closing down the siphon valve so that it can exactly handle the overflow volume completely eliminates any 'excess' drain capacity. So without a backup (whether dry or trickling), anything that even partially compromises flow in the siphon begins the process of flooding.
 
Cool setup cordell! I ordered a silencer from lifereef but have not installed it. Everything about my tank is running well and don't want to mess with the flow and adjustment of pump etc. I've been living with the gurgling but it's in my living room and the TV usually drowns out the noise.. :-) I'd deff like to address the gurgling eventually though
 
Sorry it took so long to get some pics, fishgate. I hope these will show up... trying it from Flickr.

This is the side of the overflow box that I drilled the hole for the bulkhead.


With flash...


From the top... I use a flat strainer on the emergency line to save space, and a cone-shaped strainer on the main siphon drain line (this one isn't visible).


Hope that helps...

Thanks very much that helps a lot!
 
No offense, but playing the "power outage" card against HOB overflow boxes is somewhat ignorant these days, considering that a power outage has zero effect on the Lifereef overflows.

I wish I knew how many times my power has went out in the last ten years, but I do know many floods I've had due to my overflow box losing the siphon (you guessed it, zero).

I can agree that since the tank is new, I would consider drilling, but that isn't always an option, especially with fully setup established tanks.
 
I am not worried about floods. My tank will be able to hold anything pumped up if the siphon fails and my sump will hold everything my tank will drain if the pump isn't pumping.

I'd like to drill. I will consider it.
 
If I were you I'd add a second siphon tube. Easy, cheap and gives a little insurance. I'd also think about either adding a little bleeder valve to each siphon, or rigging up a little piece of soft airline tubing to have on-hand when you get any airpockets forming to suck out the airpockets. The siphon tubes are a pain to restart and either of the above will help purge out when you get a little air gathering near the top of the tube(s).

Personally, I will not have another tank with a siphon tube overflow.
 
Back
Top