Herbie on a dual overflow

P

pjracer

Premium Member
So recently I was turned on to the herbie style overflow. Problem is my setup is a dual overflow setup. Is it possible to have the emergency overflow on one side and the herbie n the other overflow. Looking for ideas because my tank can use some silencing.

Let me know what you think. Peter
 
The difficulty lies with balancing the two water levels and preventing one from going stagnant. I have seen it work with one return on 3/4 with a durso pipe the other had a 1" siphon with 3/4" emergency, it was sucessfull.
I think a better route is to plumb both 1" dains into a 1 1/2 horizontal line with the gate valve below, that way both overflows will be balanced, use the other 3/4" drain as an emergency but keep your flow ~660 GPM (you can go up to 2,000 with increasing risk as the emergency will handle a max of 1260 with about 6" above the drain) 660 will prevent overflow in case of a total blockage which is unlikely at best, going over 1260 would not be recommended but possible.

I push about 1200 and have two screens per 1" overflow to prevent snails from blocking the gate valve. I need to remove algae about every three weeks to restore flow (the teeth in my overflow damns are the biggest restriction) (standard RR 120G dual overflows)
 
Good thought. I was thinking Of putting one emergency drain on one side and then putting the below 6 inch drain on the other side. I also looked at having the flow come out of one overflow in the return going back down under the other overflow creating a current across the tank.
 
If you have two separate over flow boxes, I don't think it will work ... the issues lies in the emergency drain ... the water in that box won't turn over at all and will just sit there ... the level may increase some, but, as the water evaporates in that box, the salinity will spike ... could cause some issues. I think the Durso may be your best bet
 
You would have water going down the emergency drain. Everything I read says a little water should flow down the emergency drain. So the water would turn over.
 
the way my Herbie fuctions is 95% of the time, the water goes down the primary drain ... it only goes into the emergency drain maybe 1-2x a week ... then, I open the gate valve a fraction to lower the level in the overflow box ... I do this b/c even with a trickle, water flowing into the emergency drain does create noise ... it is in a sitting room in our master bedroom, so, any noise is too much noise. I suppose you could set the level high enough to let some trickle in, but, you then lose some of the benefit of the Herbie
 
I only used one of the returns allowing me to have three drains, that worked great. My new system has the returns behind the tanks so I have the two 1" plumbed together and both 3/4"s are emergency lines.

You can also use one return with a Herbie, and one emergency with a herbie/or durso stand. Anyway will work fine so long as you don't use return/emergency in one overflow, better to use two herbies than one herbie and an emergency. Two herbies is a little trickey to balance but one turned down quite a bit then the other to maintain the level worked fine. Just make sure to purchase the screens or you WILL have snails getting trapped and restricting flow.

Of all three ways I have plumbed my 120 combining both 1" into a single herbie was the best method. You can use one 3/4 as return or have them both as emergencies.
 
The point of the emergency drain is to let you know the main drain has issues. I dont think you should ever have water in your emergency drain.

The simplest way to get this to work IMO is to have the emergency drain overflow higher than the main Herbie drain. You can then siphon the water out of that overflow, and if the main drain ever fails, you would have the water level in the tank rise slightly to the height of the emergency overflow, and then flow into the emergency drain. A pain I know to siphon the water out every time you fix the issue, but the only time my herbie emergency ever functioned was when I screwed something up messing around in my tank. The rest of the time, the main was fine and worked flawlessly.
 
you are supposed to have a trickle of water running down the emergency drain. Its easier to set it up that way because then you dont have to exactly match the flow rate of the return pump. And the return pump flow rate might fluctuate slightly which will affect the setting on the herbie. I just set one up on my new tank. Make sure you get a gate valve. Ball valves are terrible for this application.
 
dry or wet emergency both work, I prefer dry as a herbie will increase flow based on the water height above the herbie inlet. A small amount of water works great but it has to be very little to keep the noise down. Originally Herbies were dry emergencies with Bean Animals having the wet (durso) style with an extra dry emergency.
 
You must log in or register to reply here.
Top