The week before spring break was interesting to say the least. On Tuesday morning, March 11th, we were greeted by a fish tank with no water, a flood in the basin holding our system, and a malfunctioning pump. Fortunately, no fish died overnight. We fixed the problem quickly by removing the pump, filling the tank, and leaving the fish with an aerator. After some troubleshooting, we found out that there were a couple issues. First, the pump did not create enough water pressure to start the siphon. Also, our box leaked and nearly drained the system of water. To solve the leakage issue, we resealed the box and attached window flashes to the bottom to funnel any more leakage back into the fish tank. As for the pump problem, it appears that the best solution is to use a second pump to create a higher water pressure at the end of the wet cycle to begin the siphon. Unfortunately, this meant that the seeds could not be put into the system before spring break, but they were left to continue growing in the bag (Joe Steinmacher)
As with any new system, there is always a period of adjustment, troubleshooting, reengineering and so-forth. Our initial plan to have two pumps- one for normal duty and one for emergency backup had to be modified. After our “catastrophic failure” the solution was to leave the first pump on all the time, set to fill the grow bed approximately every thirty minutes. At the thirty minute mark, the second pump is initialized and allowed to run at full-flow, creating a surge that puts the bell siphon into operation. This second surge pump only runs long enough to get the Bell-Siphon to start. Should the grow bed happen to drain before the surge pump turns off, we’ve found that the siphon continues to operate until the surge flow ceases. At that point the siphon sucks air and the process is extinguished.
I appreciate this nice explanation of the problem you encountered. Great details!