Bucket system - HELP with syphon problem please

Happy Thanksgiving everyone. Thank you for taking the time to look. Thank you even more if you have a solution.

I have the EBB-12 Bucket system. http://www.horticulturesource.com/c-a-p-custom-automated-products-ebb-gro-12-grow-site-system-complete-w-55-gallon-reservoir-new-version-p4490/

I have one pump for FILL and one for DRAIN. The FILL pump is located in the reservior and it pumps nute water over to the smaller controller. When the controller bucket is full, a float valve shuts off the FILL pump. The problem is: when the FILL pump shuts off, it still continues to flow due to a syphon effect. This causes the controller bucket to overfill and flood my tent. It also causes the buckets to completely fill and drown my plants! All bad. A little while later, the DRAIN pump kicks on and drains the control bucket, but the damage is done.

How do I stop the syphon effect? I want the controller to stop filling when the pump kicks off.

PLEASE HELP! +rep for good solution.

My bad. I failed to read the instructions. A special "syphon break 90 degree elbow" was not correctly installed. Problem solved I think. Thank you for reading this and have a happy turkey day.

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i belive it also helps if you have the plant buckets sitting up higher on a table or something, but im not sure.

yea if the elbow duist do the job raise the conrol bucket higher than the res. or atleast run the tube up high just befor the control bucket