Our foray into the world of hydroponics, or, in our case, Aquaponics, has netted a wealth of new knowledge and a heaping helping of hindsight. The concept is great, a closed-loop system that sustains itself. Feed the fish, the fish feed the plants and the plants clean the water for the fish. Our system was successful in the realm of keeping the fish fed and healthy. We noted a marked level of growth in all six goldfish, wonderful news if we had been building an aquaculture system and not an aquaponic system.
After we solved the pump control problem, the Arduino controller worked flawlessly while performing continuous duty. Weekly, I stayed long enough to observe at least one flood and drain cycle to ensure that the surge pump was working and that there was no malfunction in the bell siphon. Unfortunately the low cost aquarium pumps proved to be just that. The number 1 pump began to exhibit signs of bearing failure about two weeks ago. The howling indicates that the annular ball bearings are failing. We decided to leave it alone. Had it failed, we would have subbed in the number 2 pump by switching the wires at the relay card. Pump 1 obviously was not up to the task of extended, continuous duty. Pump 2 has shown no signs of failure or premature wear.
We tried twice to plant lettuce seeds but they never took. While digging through the grow media, we did find one tiny seed with two little leaves. Our assumption, as with the radishes is that the hydroton doesn’t provide enough support or protection for the fragile seeds. In retrospect, we should have bedded or germinated seeds in Rockwool cubes and then placed the cubes in the hydro clay bed.
Throughout the growing process it seems as though the fish waste (nutrients) did not disperse throughout the grow bed as we had planned. The healthiest plant was always closest to the trickle of water feeding the grow bed. The indication here is that the nutrients were deposited right below it and were not migrating throughout the bed during the flood cycle. I attribute this mainly to the fact that we had to reduce the pump flow rate to a trickle that did not exceed ten fluid ounces per minute. Had we been able to run the pump un restricted, we surmise that the fish waste would have been delivered to the grow bed instead of settling out in the pump line.