herbie overflow ?
 

ok i got my new tank set up and running with a herbie, i have an external overflow box with 2 drains , then have 2 returns on the back wall, why m i getting bubbles, the water is draining down the short pipe and not the tall one, does that mean i have to cut the tall one shorter a bit

First, make sure that the short pipe is indeed running a full siphon and no new bubbles or air is entering it. If you are still getting bubbles I might know the solution.

So I actually had this issue with my bean animal when I set up my tank about a week ago. I knew everything was set right to work with no bubbles but even after 2 days of running the bubbles wouldn't disappear out of my main drain. The only reason I could come up with was that there was a leak somewhere letting bubbles enter but I saw no leak. Then it occurred to me that if bubbles are entering the pipes then the leak won't show when it's under siphon because of the pressure. So I let my drain run fully open and there it was, a tiny leak in one of the joints letting small amounts of air in. Patched it up and the bubbles were instantly gone. Give it a try.

How high is the valve on the main drain? Ideally, herbies run best with the valve low, so the entire run is full of water. If it's not full of water it's full of air...

unless you're Frank Borman, then it's full of stars. :wink:

its just a little lower then the overflow

I have same drain type but the valve is right before the water enters the sump,as wardog sad you want to have your main drain full of water at all time,and also the pipe in the overflow to be about 1 1/2" lower then the water line otherwise it might such a bit of air from the top.that happened in my tank,had it only 3/4" lower and the water draining down would create kind of a spiral and would suckered the air to ended up with bubbles in the sump..

By this description it sounds like you need to close the gate valve a bit more. I like to operate the Herbie with just a trickle going down the tall pipe (the "emergency drain", or sometimes called the "dry drain"). The emergency drain will get noisy if there is too much water going down it. You will need to do occasional adjustments to the gate valve by either opening a bit because there is too much going down the emergency drain or by closing it a bit because there is air being sucked down the main drain.

thanks a bunch everyone