Hey, the main reason your pipe siphons are not working has to do with the dumping into the 3" pipe. The height at where they fire can be adjusted by making the center pipe longer to fill your GB more.

You need to rework just one pipe siphon to get the right height first, then move on from there. The pipe siphon exist to the 3" pipe will not work because...it always need to be out of the water to gulp air in order to reset the cycle. Your 90 degree down angle going into the 3" pipe needs to be turned to the right about 90+ degrees. In order to create enough water resistance to completely fill the pipe and fire the siphon.

Instead of a 3" pipe I would try a large rain gutter or some other type of open gutter. Your pump needs to puts out enough water to fill all GB's at the same time and still return about 1/3 to 1/2 of the water output back the to FT or sump as splash down.

It doesn't matter if they all fire at differ times...better if they don't, try for a 8 minute fill with a 4 minute drain. Once you get your center pipe the right height at the 8 min. fill & 4 min. drain. Then do #2, the more GB's you bring online the more water will be diverted from your splash down to your GB's. Repeat #3 and so on.

You can call me on my cell phone I'm on Verizon, it will not cost me anything or I can call you on my land line...I got free long distance.

Your so close, HANG IN THERE!!!!!!!!!!!! Apollo