Today we finally began growing our plants. Because we are starting out with seeds, we decided to germinant extra seeds, hoping half of them will grow. We wrapped six lettuce seeds and six radish seeds into a wet paper towel and put the paper towel in an open zip seal bag (Joe Steinmacher)
While Joe was starting our (hopefully) plants, we set the water pumps in place and hooked up the tubing and ball valve. Mark and I secured the ball valve and tubing to the side of the grow bed. We removed the aeration pump because the ebb and flow cycle should introduce oxygen into the water as it drains through the grow bed and is returned (via the Bell Siphon) to the aquarium. In reference to our necessary bacteria, while securing the pumps in the tank bottom I noticed a fine sludge had begun to form. Good news for us; the fish byproduct is what ultimately feeds the plants. We must note that the control system for the pumps is not installed at this time as we are still awaiting sensors (coming from China). To make the pump operate, we simply wired the leads through the Normally-Closed side of one of the control relays.
We metered the pump flow using the ball valve and measured the time it takes to move approximately ten fluid ounces from the aquarium to the grow bed. Ideally we should see about ten ounces every sixty seconds. We were able to meter the flow to about fifty seconds per ten ounces. At this point it appears to be a small trickle. While it seems slow, we must keep in mind that we need to move approximately two gallons of aquarium water up to the grow bed over a thirty minute span, followed by immediate draining. When the grow bed reached it’s drain point, we soon discovered that in-flow in the siphon was too little and that a vacuum wasn’t being created to initiate the siphon. The overflow was merely matching the pump flow. For the time being we decided to open the ball valve to 100% and to ignore the timed ebb-an-flow cycle because there aren’t any seeds in the grow bed.