Full siphon?

[3rdMoon]

I’m gonna go ahead and ask this question even tho everyone reading it will think I’m an idiot. What exactly is a full siphon? I read so many posts and where people say things like “I’m running Bean Animal. One full siphon, one partial, and one emergency” What does that mean? What is a full siphon? And why is it important?

 

[scottedontknow]

Hehe just means that your main overflow is sucking water without pulling any air (air makes the gurgling sound) we fine tune that siphon with a gate valve

 

[JoshH]

Standard terminology for drain setups, basically your main or full siphon drain handles 99% of the flow in Herbie, Bean Animal/Modified Bean Animal drain setups and 100% of the flow in a Durso drain.

With a Bean Animal/Modified Bean Animal it's setup like this...

99% Flow down main/primary drain (Full Siphon)
1% flow down your secondary drain (Partial drain)
0% flow down the emergency drain (A backup incase both others fail)

Herbie Drain Setup

99% Flow down main/primary drain (Full Siphon)
1% flow down your secondary drain (Partial drain)
No secondary emergency drain

Durso Drain Setup

100% of flow down the main drain
No secondary drain or emergency drain

In the first two setups you typically use a gate valve on the primary drain. This let's you tune the flow (Siphon) to get the balance mentioned above without sucking in any air as mentioned above as well, tuning is key as this is what makes these systems super quiet.

 

[3rdMoon]

Hehe just means that your main overflow is sucking water without pulling any air (air makes the gurgling sound) we fine tune that siphon with a gate valve

Ahhh... and that’s accomplished by restricting the overflow with a gate valve?

 

[3rdMoon]

Standard terminology for drain setups, basically your main or full siphon drain handles 99% of the flow in Herbie, Bean Animal/Modified Bean Animal drain setups and 100% of the flow in a Durso drain.

With a Bean Animal/Modified Bean Animal it's setup like this...

99% Flow down main/primary drain (Full Siphon)
1% flow down your secondary drain (Partial drain)
0% flow down the emergency drain (A backup incase both others fail)

Herbie Drain Setup

99% Flow down main/primary drain (Full Siphon)
1% flow down your secondary drain (Partial drain)
No secondary emergency drain

Durso Drain Setup

100% of flow down the main drain
No secondary drain or emergency drain

In the first two setups you typically use a gate valve on the primary drain. This let's you tune the flow (Siphon) to get the balance mentioned above without sucking in any air as mentioned above as well, tuning is key as this is what makes these systems super quiet.

Wow! That’s a very comprehensive answer. So my CPR Aquatics CS102 HOB overflow is crazy loud. If I install gate valves on both overflow drains it’ll run quietly?

 

[JoshH]

Wow! That’s a very comprehensive answer. So my CPR Aquatics CS102 HOB overflow is crazy loud. If I install gate valves on both overflow drains it’ll run quietly?

Being a HOB model I'm not 100% sure you can set it up that way. I would not put a valve on both drains but you could install a gate valve on one and put a small pipe extension on the other inside the box itself. This would essentially turn it into a Herbie drain setup. How much flow are you getting from your return pump?

 

[3rdMoon]

Being a HOB model I'm not 100% sure you can set it up that way. I would not put a valve on both drains but you could install a gate valve on one and put a small pipe extension on the other inside the box itself. This would essentially turn it into a Herbie drain setup. How much flow are you getting from your return pump?

The overflow is rated at 1200gph but my return pump only maxes out at 1056gps. When I turn the return pump to 10 (full blast) the overflow gurgles even louder and burps a big splash of water into the sump every minute or so. I have to turn it down to 3 to limit that. But for some reason the rear chamber of the overflow (where the bulkheads are) doesn’t fill more than a few inches. It doesn’t even cover the screen fittings in the bulkhead. Everything’s brand new. Been up for exactly 2 days.

 

[JoshH]

You'll have to forgive me as I've never personally set up a HOB overflow, certainly not a dual pipe version either. But I would try and set it up as I mentioned above. Install a gate valve on one of the lines and the other add a small section of pipe on the inside of the overflow. Then tune the valve until theres the smallest trickle of water flowing down the pipe on the secondary drain

 

[3rdMoon]

You'll have to forgive me as I've never personally set up a HOB overflow, certainly not a dual pipe version either. But I would try and set it up as I mentioned above. Install a gate valve on one of the lines and the other add a small section of pipe on the inside of the overflow. Then tune the valve until theres the smallest trickle of water flowing down the pipe on the secondary drain

I’ve seen that set up on YouTube but only on drilled tanks. Unfortunately I bought a tempered tank before I realized you can’t drill them. I ended up having to go HOB. Frustrated (and being a rookie) I just ordered the biggest, most expensive HOB I could find. It seems I’m still paying for my impatience and frustration. Thanks so much for your input! I’ll order a gate valve today.

 

[RocketEngineer]

To add clarity: the “full siphon” means the pipe is totally full of water and is moving as much water as can flow through that pipe. In the case of the drain setup, the goal is to almost balance the return pump in with the siphon line out. To do this, we use a gate valve as it gives us lots of control and allows for fine adjustments vs say a ball valve.

This is important because a siphon, once it gets going, is very quiet for the amount of water being moved. By not having air, you don’t get the waterfall noise from the plumbing. The catch is if it gets clogged, now you have no drains and flood your house. That’s why there are 2 (Herbie) or 3 (BeanAnimal) pipes. The backups are there in case the siphon gets clogged. HTH.