Sump pump size...

[mike31154]

The way he described his overflows (post #8), the extra, or return holes are drilled outside of them. He'd have modify or move the overflows to include these outside holes (or plug them?) to do the Herbie using all drilled holes.

[sphelps]

Originally Posted by mike31154

The way he described his overflows (post #8), the extra, or return holes are drilled outside of them. He'd have modify or move the overflows to include these outside holes (or plug them?) to do the Herbie using all drilled holes.

IC, in this case I would personally wouldn't use a standard herbie design, I think using a second overflow with the purpose of emergency only will lead to problems as already stated such as stagnant water even if it's higher as water will still sit around the bulkhead which could lead to mold growth and that algae smell. What I would do is use the one overflow as a primary to take the majority of the flow, you can still set it up with a gate valve but adjust it so a small amount of flow still goes through the second overflow which would have a durso standpipe. Setup the durso so it has a small siphon break hole and a longer downspout, if the primary clogs up the durso will siphon under the higher load to prevent tank overflow. The second overflow will need to be slightly higher but nothing significant, a layer of silicone should be sufficient.

[Lampshade]

sphelps is right with the problem waiting to happen. I'm currently runnign that setup, since i only have 2 holes drilled in my tank and i'm running a herbie. A herbie emergency drain should be bigger than the original, mine is not. I've got the main fairly restricted, but if it was to 100% plug, there would be problems, i don't think the second overflow could handle 100% flow. It would top the overflow and still make the drain, but my tank would be near/at 100% full.

As for the stagnant second overflow, i have a 1/4" hold drilled about halfway down my emergency drain, keeps a bit of flow, but still lots of sediment at the bottom of the overflow.

But yes, i would recommend another hole drilled to run a herbie (a 2" if your main return is 1.5"), it's silent. There's lots of other setups around too, i like the stockman, or the Beananimal mentioned is a great one as well. All preference.

[mark]

From first hand experience have to disagree that a modified Herbie is a problem waiting to happen. Mine's been up since last October, water in the 2nd chamber can't be that bad as snails don't seem to find it a problem. As for sediment, what's in the overflow is what's left from when I pulled out the Durso. If it was a problem guess I could just siphon out when I did a water change.

Idea for the emergency being a Durso is interesting but since I'll need to worry about flooding at 2000gph if the primary became blocked, I'd be reluctant having the emergency standpipe anything other than a open pipe.

Drain size, here's a calculator for a guide, (towards bottom). 1.5" should be able to handle a Dart.

[hdrob]

Maybe I'll start with a durso or stockman setup first and if that's not quiet enough, try something else?

Beananimal is out, I have single-hole corner chambers.

Thanks for the input!

-Rob.

[sphelps]

Originally Posted by mark

From first hand experience have to disagree that a modified Herbie is a problem waiting to happen. Mine's been up since last October, water in the 2nd chamber can't be that bad as snails don't seem to find it a problem. As for sediment, what's in the overflow is what's left from when I pulled out the Durso. If it was a problem guess I could just siphon out when I did a water change.

Idea for the emergency being a Durso is interesting but since I'll need to worry about flooding at 2000gph if the primary became blocked, I'd be reluctant having the emergency standpipe anything other than a open pipe.

Drain size, here's a calculator for a guide, (towards bottom). 1.5" should be able to handle a Dart.

Well provided it was maintained it may not cause a problem, but why bother adding something that does little good and requires extra maintenance. Using a whole overflow box for emergency reasons only is a waste, 99.9% of the time does nothing but take up space. The reason Herbie overflows have the second drain is because the first is so fine tuned that very minor changes can cause the water to back up but the chances of the primary drain actually clogging 100% is very unlikely. Overflow boxes should always be screened to prevent large enough objects from clogging the drain. Most people don't run Herbies and many only run a single drain, I've personally never seen a or heard of a full clog before with a standard overflow setup.

In addition if you setup the Durso properly it will siphon at higher flow rates and extending the downspout to the bottom of the overflow box will actually add head pressure and will be capable of flowing more than a straight pipe that is typically used in a Herbie setup. Plus on top of that using the standpipe will allow more freedom in tuning, if your flow increases or decreases slightly you will not have to adjust the valve like you would on a typical setup. Lastly by sending some water to the second overflow you eliminate the questionable stagnant issue and you get the benefit of more surface skimming by actually using that second overflow for the purpose it was intended for. There really is no downside to this and I've always setup Herbies in this fashion.

[mark]

Main reason I went Herbie was noise from the air in the lines. The display itself with Dursos was near silent but the gurgling finally became enough. Can't see going back.

If was to do over again from the start, would definitely layout for the Herbie the primary and emergency standpipes in the same chamber. I've got an established tank, basement sump and now a finished basement so to either cut out the overflow (then I'd have my return and emergency bulkheads open on the floor of the tank) or to swap my drains with my CL inlet just isn't worth the hassle.

To the OP, you're got a dry tank now, enlarging the overflow chambers to accept a second (or 3 bulkhead) to get right from the start, might be something to consider.