Nice work untamed. I think ill be doing this mod 2 on my build thats coming up in the next month or 2.

I think that this mod is limited in its ability to quiet things down because:

In order to have the 'back up' drain work, the top of it would have to be lower then the high water level in the skimmer box - in order for it to flow as water level rose. Meaning that you would have to have your water level in your overflow box lower then normal. Thus alot of the benefit to having a quiet drain would be removed because you would have a louder overflow.

That's true. If the water falls very far in your overflow box, it can make noise. Also, if the water falls too far, it can push air bubbles into your primary drain, which also causes noise. However, if you tune the Herbie to it's optimum, you would have the overflow box water level right at the emergency level. In fact, if some water trickled down the emergency that would be nearly perfect.

That would have the water line much higher than I've drawn it. Some testing would be required to get the emergency overflow at exactly the best height.

so is this more like what your thinking untamed?

http://i265.photobucket.com/albums/i.../Modherbie.jpg

That mod is asking for it. Snails will block bulkhead drains left, right and center.

That looks like it will work. I agree with Albert - But I think that could be overcome by a huge strainer valve. Really no Different from using only one drain and one return.

I think that this has potential to be a really good alternative for those wanting the performance of a herbie, but only have one hole drilled and have the ability to run plumbing up the back / side of the tank. However it would be very finicky and an inferior design to a herbie for a new build.

I was thinking a strainer would overcome the snails cloging up the unit as well. And yes, i know this would be an inferior design to the real herbie, but for guys like me that have a system with only one hole drilled then this "Untamed" :wink: overflow design will be better then a durso.

Yes, but you could make that emergency overflow loop even higher than you've drawn so that the water doesn't fall so far inside the overflow box.

Yes, true...but that doesn't have anything to do with the mod. If you have only one drain or bulkhead, that's always a risk. You could still apply every trick already available to prevent blockage and it would have no affect on the performance of this modified Herbie.

This is a Herbie mod for someone who wants the performance of a Herbie, yet is stuck with the limitation (and risk) associated with having only 1 drain hole.