Herbie Method for double overflow boxes?

[Texastravis]

Looking for some advice on running the Herbie Method on dual overflows. I think I would actually have to run the two overflow lines together at a 'T' then have a gate valve?

If this is the case I am looking for some advice on line sizes. My bulkhead holes are sadly only 1" right now with a 1" standpipe. So should my sizes be 1" standpipe to a 1" bulkhead to a 1.25" pipe to join with a 1.25"-1.25"-1.5" Tee?

I will try to draw up what I am thinking. I really want to do this right and get all the pipe sizes right. I will be running at max flow. My tank is a 300 gallon and I have a 3600 GPH pump so I might have to tone it down some. How much flow can I expect to get?

Thanks, all suggestions welcome.

[DustinB]

This probably won't help much but I have a 90g with a 1" drain pipe. I used the thin wall, HD carries it, not Lowe's. I'm running a mag 9.5 at about 800gph after head loss. I have the gate valve closed easily 2/3 to 3/4 of the way.

This siphon method allows for far more water to drain than a durso due to no air being drawn taking up space.

I know people have done it both ways with dual overflows, either way you still have to tune it in to stay constant. My guess would be to use 2 x 1" thin wall lines. You can use regular 1-1/4 pipe under the tank for strength so you still have a 1" ID. Based on my flow you may be able to get close to that with dual lines.

Remember, you can divert some of the return power to the refugium instead of just dialing back pressure.

One tip I would advise either way, give yourself at least 1.5 to 2" height difference between the siphon lines and the backup lines. There will be a variance in the overflow box level at difference times of the day. I ended up with a 2" difference to not have to adjust the water level at all anymore.

Hope some of that helps...

[Texastravis]

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[Texastravis]

My main concern is if converging the two lines together is the right thing to do and if 1.5" is big enough to do that for NOOOOO NOISE lol.


This probably won't help much but I have a 90g with a 1" drain pipe. I used the thin wall, HD carries it, not Lowe's. I'm running a mag 9.5 at about 800gph after head loss. I have the gate valve closed easily 2/3 to 3/4 of the way.

This siphon method allows for far more water to drain than a durso due to no air being drawn taking up space.

I know people have done it both ways with dual overflows, either way you still have to tune it in to stay constant. My guess would be to use 2 x 1" thin wall lines. You can use regular 1-1/4 pipe under the tank for strength so you still have a 1" ID. Based on my flow you may be able to get close to that with dual lines.

Remember, you can divert some of the return power to the refugium instead of just dialing back pressure.

One tip I would advise either way, give yourself at least 1.5 to 2" height difference between the siphon lines and the backup lines. There will be a variance in the overflow box level at difference times of the day. I ended up with a 2" difference to not have to adjust the water level at all anymore.

Hope some of that helps...

Thank you, I didnt even think about using thin walled pipe! Good idea!

[troylee]

your design would work but i would keep the drains seperate....
fwiw i used 1.5" drains and my dart 3500gph on a fully open sphion still used the open channel slightly.... it really depends how creative you get with the return etc.... the more head loss the less flow as we all know...;)

[Texastravis]

your design would work but i would keep the drains seperate....
fwiw i used 1.5" drains and my dart 3500gph on a fully open sphion still used the open channel slightly.... it really depends how creative you get with the return etc.... the more head loss the less flow as we all know...

I "thought" I read that when using the Herbie method it is difficult getting things to consistently stabilize with 2x overflow boxes and that it might be best to combine/join your drain lines to a single bulkhead. Again, this is what I though I heard but was looking for some more insight.

[trilinearmipmap]

I really suggest having two separate gated drain pipes rather than joining them together and having one gate valve.

The amount of water flowing into the left and right overflows will vary over time. Factors include powerheads pushing more water to one side of the tank, partial blockage of the overflow grating, etc. You want to be able to raise or lower the water level in each overflow independently.

I have run Herbies on a dual overflow 120 for about 5 years or since the Herbie thread first surfaced. From time to time I need to adjust the gate valves a little but for the most part the overflows are silent.

[Texastravis]

I really suggest having two separate gated drain pipes rather than joining them together and having one gate valve.

The amount of water flowing into the left and right overflows will vary over time. Factors include powerheads pushing more water to one side of the tank, partial blockage of the overflow grating, etc. You want to be able to raise or lower the water level in each overflow independently.

I have run Herbies on a dual overflow 120 for about 5 years or since the Herbie thread first surfaced. From time to time I need to adjust the gate valves a little but for the most part the overflows are silent.

Thank you very much. I thought that two separate ones should work. I am going to dig through the Herbie thread one more time and see if I can fine anything more.