Any one have a diagram of a "herbie"? I haven't of this and I am interested.

ok, so basically what im getting is that you make 2 holes, and connect PVC to one and then some sort of flex tube or more PVC, and make sure one elbow or whatever you use is above the water line for emergency use, and you put a gate valve on the PVC and adjust it until there is no sound

Simply, a Herbie is nothing more than two standpipes in a overflow chamber, one higher (secondary or emergency) than the other and the lower one (primary) having a valve on the drain line just above the sump.

The valve is closed until the water flowing into the primary is over the top of the standpipe and not drawing air. The secondary is higher than this water level and is normally dry. Purpose of the secondary is since the primary is already restricted and backing up water, if the was to become more blocked it would overflow the tank, the secondary prevents this. Often the primary drain output is a little below the water level in the sump, the secondary just above. If you start hearing water splashing from the secondary, it indicates the primary needs to adjusted or has gotten a blockage. Combined with a ATO they are set and forget though.

The huge RC Herbie thread

Also check out Reefjunkie non-traditional Herbie layout here

okay, kool!
i think i will do almost exactly what reefjunkie did, just a little different plumbing near the bottom because my sump hangs out the back of my stand

I know for sure that the Herbies where the standpipes are on the bottom work and see no reason why having the drains on the sides in a short overflow chamber wouldn't work but might contact reefjunkie, and after seeing JDigital build, him for feedback.