Herbie Drain - Return Chamber Inconsistent

[pelphrey]

Hoping I can get some pointers on the herbie! I'm running this drain on a 27 gallon cube with the eshopps nano cube sump. Both drains are 1'', main drain has the strainer on it. I modified the sump (you can see in the red the section I cut out) to better fit my plumbing. The sump originally came with a filter sock and 2 filter pads. I have removed all 3 to increase water flow. When the water enters the sump it goes in 2 directions. The 1st being into the fug which then travels directly into the return section. The 2nd direction is the filter sock compartment (no filter sock) into the skimmer section and into the return. I am running a sicce 1.5 return pump and the eshopps psk75 skimmer.

My siphon (main drain) works flawlessly. The problem is my return chamber fluctuates heavily and is very inconsistent. So inconsistent that I haven't added an ATO yet, I don't want to create a flood and create huge swings in salinity.

I've thought about adding a "T" to the return pump with a ball valve and either directing the water into the skimmer section or directly back into the return section to see if this will help. Before I make any modifications to the return plumbing I wanted to ask here before hand.

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[Drauka99]

I am having a tough time visualizing how this is happening. if the drain is running correctly then there shouldn't be any fluctuations.... it almost sounds like you are not getting a full siphon on the drain and it is flushing, at least partially. With a 1" at full siphon the gate valve should be almost completely closed with the gph of the return pump. You are setting it where there is a slight trickle going through the emergency drain, right?

Can you flip the full siphon line upside down? you need some head pressure on the siphon line to keep it at full siphon as well.

 

[TheEngineer]

Is the level in your overflow fluctuating?

 

[pelphrey]

I am having a tough time visualizing how this is happening. if the drain is running correctly then there shouldn't be any fluctuations.... it almost sounds like you are not getting a full siphon on the drain and it is flushing, at least partially. With a 1" at full siphon the gate valve should be almost completely closed with the gph of the return pump. You are setting it where there is a slight trickle going through the emergency drain, right?

Can you flip the full siphon line upside down? you need some head pressure on the siphon line to keep it at full siphon as well.

After doing some research I think I may try to get the gate valve down some and try that. I am not running the emergency with a trickle, from what I have read the majority of people leave this drain dry.

Is the level in your overflow fluctuating?

It does. If I add a cup of water to my return section the overflow level will rise.

 

[TheEngineer]

It should rise if you add water to it. I meant when running normally does it fluctuate. Reason I ask is that the water is coming from somewhere so we need to figure out where it is coming from and where it is going.

 

[Drauka99]

I run the second drain at a very slight trickle...think drops per hour. Once I finally set mine this way then I no longer had any issue with the overflow section fluctuating.