Herbie on dual overflow
- Thread starter vbsaltydog
- Start date
I have a 120 with dual overflows. I keep going back and forth with this. I am starting to think that doing the herbie on one side and the return on the other side with the 3/4 capped and the 1 inch as the return with 2 locline noozles.
Does any oe have a picture or dioagram of this?
Does any oe have a picture or dioagram of this?
Another question it seems like there are differing ideas of what the siphon pipe should be in the overflow. Higher means less water in the sump if the return pump shuts off. Lower means more water movement in the overflow itself. I am inclined to go with higher and a small power to move the water around the overflow, but if I go lower and the pump fails the siphon can't pull in more water then is in the overflow correct? Once the pump fails the water in the DT will fall to just below the level of the inlet slots of the overflow tower correct?
acesq
Premium Member
Correct. The siphon pipe will only pull the water in the box down to the level of the top of the pipe, assuming, of course that the pipe has a water tight connection to the bulkhead, which is usually accomplished by a press fit. The overflow box will take in water from the tank to the bottom of the teeth. Keep in mind that your return lines will back flow water from the tank to the level of their output. That typically results in the majority of the water that makes its way back into the sump when the return pump power is cut.
perverseosmosis
Member
I finally moved my setup out of the garage and into the house. It's been a few weeks and so far, the levels have been completely stable and the plumbing has been dead quiet. So quiet that now I'm on to the more difficult task of quieting the skimmer. :hmm5:
o = 3/4"
O = 1"
..A.....B
[o O] [O o]
.1.2...3.4
Compartment A (flooded):
1) Return pump (out to display)
2) Syphon + gate valve
Compartment B:
3) Open drain <---trickle of system-balance slop goes here
4) Syphon + gate valve (level set at whatever)
To recap, the vast majority of the water ends up going down the two syphons. Syphon 2 is gated enough to keep the level in compartment A flooded. Syphon 4 is gated just enough to keep the level in compartment B high enough so it trickles over open drain 3.
None of the drains are T'd together. All syphons and the drain open high enough in the overflows, that if the power goes out, the sump must accept at gallon or so of water. Nothing too much.
That only leaves the stagnation question. I'm reluctant to put a powerhead back there. It would be the only thing hanging over the lip of the tank. If it comes to it, I think I'll widen the syphon break I have in the return pump lock-line and angle a small jet of water downward to mix things up.
o = 3/4"
O = 1"
..A.....B
[o O] [O o]
.1.2...3.4
Compartment A (flooded):
1) Return pump (out to display)
2) Syphon + gate valve
Compartment B:
3) Open drain <---trickle of system-balance slop goes here
4) Syphon + gate valve (level set at whatever)
To recap, the vast majority of the water ends up going down the two syphons. Syphon 2 is gated enough to keep the level in compartment A flooded. Syphon 4 is gated just enough to keep the level in compartment B high enough so it trickles over open drain 3.
None of the drains are T'd together. All syphons and the drain open high enough in the overflows, that if the power goes out, the sump must accept at gallon or so of water. Nothing too much.
That only leaves the stagnation question. I'm reluctant to put a powerhead back there. It would be the only thing hanging over the lip of the tank. If it comes to it, I think I'll widen the syphon break I have in the return pump lock-line and angle a small jet of water downward to mix things up.
vbsaltydog
Member
To combat the collection of stagnant water in the flooded overflow, just pull the stagnant water when you do your water changes. Its adequate to keep the overflow water clean and it helps to encourage regular water changes.
perverseosmosis
Member
That'd work too. It'd actually be nice if all the gunk collected back there and I could get it in one go. I'm probably not that lucky.
That'd work too. It'd actually be nice if all the gunk collected back there and I could get it in one go. I'm probably not that lucky.
I'm just learning about Herbie's and BeanAnimal's and still trying to figure the way to go. I have dual overflows close to each corner of my 96 X 30 X 30 that I just got. I have 1.5'' drain holes in each overflow as well as 1'' return holes. Is it possible to do the syphon drain on say the left overflow and the emergency drain on the right overflow? How much syphon flow would I get on a 1.5'' drain?
After reading through this, is the only concern with this setup stagnant water on the right overflow? If so, would drilling a few 1/16'' holes up the stand pipe of the emergency drain on the right overflow get water moving enough in that overflow to combat stagnant water? Just a thought and no idea if it'd be effective (or disastrous).
perverseosmosis
Member
Ideally, you want your open drain to be big enough to handle the return pump's flow, should one or both syphons plug up with snails, trout or whatever else you're keeping
. If your 1.5" syphon (or syphons) are gate-valved down to match your return pump's output, their diameter could actually be fairly small. Leaving your remaining 1" drain to handle your return flow. On a 375g tank, maybe that's dicey. I dunno.
Disturbing the water column along the drain is an interesting idea. I don't think I've seen it discussed. You should do it and tell us how it works and if it makes any noise!
One thing to consider is that when you shut off the return, your overflows will empty into the sump down to the level of the lowest hole.
I have this problem in my current setup. The seal between one of my standpipes and the bulkhead leaks. If I leave the return off for a few hours, the level in my sump rises a couple inches as the overflow empties
My sump isn't very big, so it's a concern. Keep us posted on what you do!
I am about to setup a Marineland 265 with dual corner overflows. My plan is to do a standard Herbie in one overflow and a durso/return in the other. I will dial the siphon back such that the durso runs enough water to prevent stagnation. I am not a huge-flow-thru-sump proponent, so a single return will suffice.
I didn't think that part through. It'll definitely drain down to the lowest hole and flood the sump (in my case at least).
If I went:
O o o O
1 2 3 4
1 - Open/Emergency Drain
2 - Siphon Drain directly to sump (not T'd with 3)
3 - Siphon Drain directly to sump (not T'd with 2)
4 - Return
O - 1.5''
o - 1''
My thinking is that if 2 1'' siphons were to both get cloggged up for some reason, wouldn't it require a larger hole, the 1.5'', as a failsafe to support their flow? I've been reading through this thread and see several posters going with the emergency as the smaller of the two holes with the 2 siphons on the larger openings. Wouldn't it make sense the other way around, for failsafe purposes, or am I thinking about that wrong? Obviously the chance of both siphons getting plugged up at the same time would be very rare, but you never know.
I'm trying to generate a flow of 2,000-2,500 gph to my sump (which wouldn't be possible with dual Dursos), and would think 2 1'' siphons might get me there, where the 1.5'' open/emergency should solely be able to support that amount should there be some clogging.
With a siphon in each overflow, I shouldn't have to worry about water becoming stagnant either, right? Thanks ahead of time for feedback.
CoralReeForrest
New member
Seeing as I'm ok with my return being over the tank, I'm glad I found this thread. I have two overflows, one on each side and in theory this sounds like it will work perfectly! Will report back this weekend when I do it!
perverseosmosis
Member
I agree. (My open drain uses the larger bulkhead)
What's the level of the water in the chamber containing 3 and 4? There's no open drain to tie the level to, so I'd think you'd have some difficulty keeping the level (and siphon) constant.
I solved this by filling the chamber with the return in it to water level of the display itself. There's enough water returning to the tank that the siphon in that compartment never pulls enough to drop. That extra slop then goes down the big drain in the other compartment.
However, because there's no tumble, there's likely not as much churn back there. It's not high on my problems list. If it was, I'd route a 1/4" tube off the top of my return and aim it straight down to stir things up.
CoralReeForrest
New member
Sort of a modified version, the emergency is having an overflow in the sump. Dead silent. Absolutely love it.
vbsaltydog
Member
I DO NOT recommend tying the open drain line into the siphon line. The open drain line is mostly flooded in order to establish the siphon on the siphon portion of the shared line. If your single line gets clogged low enough, the emergency drain will fail along with the siphon and you will have a flood.
CoralReeForrest
New member
Good point, I don't know if I'd ever have a clog though both overflows have drain guards on them.
vbsaltydog
Member
The chance of a clog is minimal but if there is ANY chance, it will probably happen sooner or later.
CoralReeForrest
New member
However, assuming that the main got clogged, the return section would run out of water quicker then it could be replenished so I don't think it would end up flooding. Before it gets in the house though I will run multiple scenarios.
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