Another plumbing question - Herbie Setups (1 Viewer)

[scyre]

So I understand the purpose of a Herbie and how it's setup, but I have a question to all those that currently employ this method:

If the system is setup such that the amount of water being pumped into the main system and the amount being drained through overflows is identical, won't the water in level in the overflow still go down over time as a result of evaporation? The water level of the tank will always remain constaint since its constantly being pushed through the overflow and the water level in the sump will effectively stay constant because it's semi enclosed.

This means that I would constantly have readjust the water level in the overflow with the gate valve to offset evaporation levels. If I need to leave for 2-3 days, the tank would easily evaporate 3-4 gallons, far more than I have available to evaporate in the overflow before the water level reached the top most level of the herbie.

On another note - are there suggested flow rates through the sump to effectively turn the water over in the tank? The tank is a 135 gallon - after employing the Herbie system (i.e. one drain), if I run both of my OTP-2000 open, the water level in the tank is considerably higher than when I ran two dursos (over two different overflows). The higher water level then contacts the center brace which is 1/2" glass, and likely would build with salt creep.

I believe i'm limited by the length of baffles available on the overflow (which I've cut in half now with the Herbie since I the second drain became the emergency). If I turn one pump off, the water level returns to the same as it was with the Durso's. Would I be safe running a single return line with the OTP-2000 (500gph not including head pressure) and changing the 2nd return to another emergency drain?

 

[Rachelle V]

I hope I say this right, someone correct me if I'm wrong...

The tank and overflow levels remain constant. The chamber in your sump that has the return pump is where the water level will decrease as water evaporates. I rarely adjust the gate valve for the overflow.

 

[nelsonmarine]

I have the Herbie style plumbing and I like it a lot. It was my first plumbing system and super easy and very intuitive.

At the beginning, you'll need to play with the gate valve to adjust water levels to appropriate levels in the overflow. It will eventually hit an equilibrium level after a while.

Your evaporation will come from the sump. If you think about it, a constant amount of water is being pumped into your tank from the sump. That water rushes into your overflow. If you have equilibrium, the water levels will begin to stabilize and not change very much in the tank and overflow, regardless of evaporation.

For example, if you have your overflow at a level you are happy with, try filling the overflow (or empty the overflow) with water. After a few hours, or less, that water level will stabilize and go down to it's original level. Sorry for such a long explanation, but that's my 2 cents.

 

[Merkurfan]

Everyone is right. The level will change in the pump chamber. welcome to herbie heaven.

 

[scyre]

For example, if you have your overflow at a level you are happy with, try filling the overflow (or empty the overflow) with water. After a few hours, or less, that water level will stabilize and go down to it's original level. Sorry for such a long explanation, but that's my 2 cents.

This is the part I'm struggling with though - if you don't change any of the import and export rates and you remove water from the overflow, how will the pumps ever catch back up from the water that was just removed?

Only thing I can think of is a the slight loss in pressure from the overflow will cause the flow in the drain to slow down ever so slightly forcing the water level to rise back to its equilibrium state, but I would have thought that to be insignifcant when compared to the flow rates typically seen.

 

[nelsonmarine]

Yea, it's complicated now. Hehe. Sorry, I tried. I just don't lose enough water where my levels are a concern. I'm sure more advanced aquarists will chime in.

Bump.

 

[Merkurfan]

This is the part I'm struggling with though - if you don't change any of the import and export rates and you remove water from the overflow, how will the pumps ever catch back up from the water that was just removed?

Only thing I can think of is a the slight loss in pressure from the overflow will cause the flow in the drain to slow down ever so slightly forcing the water level to rise back to its equilibrium state, but I would have thought that to be insignifcant when compared to the flow rates typically seen.

It's how gravity affects it. More water on top of the stand pipe the faster water is pushed/pulled through the gate valve. Less water at the top and the water will flow slower due to less pressures.

It's hard to explain how it works, it just does

 

[agears]

I've been running the Herbie Method for about 3 weeks as a noob here. My evaporation on my 125g comes from the return chamber of my sump (1-2 gallons a day). I do have to adjust my gate valve just a hair every once and a while as my overflow chamber will vary 1-2", but I figure it's still breaking in or I haven't goten that magic spot yet. However I just put in a refugium, without the herbie method, and it sounds like a monster has indigestion every minute or so! haha I'll fix that soon enough.