dual overflow herbie single drain psa

i have a dual corner overflow tank and was running a non functional bean overflow. didnt really work right with my dual overflows and ultimately to get it silent had to run water so high it was just a herbie with 2 emergency drains. changed things up and ran a herbie in each overflow. didnt balance well. i was running filter socks in my 40 breeder sump for mechanical filter. wanted something less involved and purchased a clarisea sk5000 g3. good bit of gear btw. because i was now running two drains and didnt want to buy two rollermats, i started searching for how to single drain my dual overflow herbie. for a week i looked. every thread that asked ended up so back and forth with no conclusion of will it work. each thread i found was full of people saying it wont work and dont do it.. in the original herbie thread back in 2004 page 47 i saw pictures and reference of people doing it. so this past weekend i bought some pipe and started testing. my particular tank has 2 1 inch bulkheads in each drain. so i made a balance pipe thing that was made from 2 inch pvc. details dont matter other than it was loud until everything equalized. it only had 1 gate valve on the discharge to sump. didnt like it.

final result of a little trial and error was this... mix of 1 inch pvc and soft silicone tube from brs. because its just how it worked out and was easy to plumb. took 10-15 minutes to adjust valves to be silent and stable. i have a dc return pump but we all know how to throttle ac return pumps. ran my dc pump as high as my emergency drains could handle and then adjust my gate valves to silence. one overflow water level is a bit lower than the other but cant say my tank is 100% level and flow into overlfow is gentle enough that it doesnt make noise. i also ended up running my return up over the edge. nothing elaborate. i have two emergency drains, one in each corner. its been tested for complete reliance on emergency drain should failure happen. does the single drain need to be centered? i dont know didnt try. this is just what i did. on power out it restarts quick and goes silent fast enough. fyi, yes the sk5000 hang on brackets will fit a 40 breeder top frame with no modification.

it was hard to find FIRST HAND experience of trying or doing this. so hopefully someone can find this helpful and easy to find. props to that original herbie thread.


  • dual overflow herbie single drain.JPG
    dual overflow herbie single drain.JPG
    64 KB · Views: 6


Who Am I Here?
Premium Member
That’s great to know! @jtadams this might be something to consider if you plan on doing more than one stand pipe? I know you were thinking a bean animal but just thinking outloud


New member
Yessir!! Thinking the bean animal may be a bit too complicated where a Herbie should work just fine. Will likely take the advice of Tenacor and use soft / flex pipe for the drain to help quiet things down as well..

From what I've read, rather it be a pressurized system or drain, pipe length does matter. I would think centering the drain between the two would help with a consistent even flow through the valve. Maybe this is where the initial noise is coming from and/or the 90s (elbows) if that's what's installed at the bottom of both drains? Also want to make sure there's pitch to the drain lines, really don't want them level if you can help it (y)