System 2.5
While putting together this next system information I realized that when talking about my first two systems I left out a very important detail.
My pumps were running on a timer. On 30 mins, off 30 mins. This was intended to make the grow beds flood and then drain (ebb and flow). Plant roots need oxygen and this helps aerate the grow bed. I tinkered with different time intervals and i cannot say one is better than the other. A constantly flooded grow bed is also an option as long as you 1) keep your dissolved oxygen (DO) up AND 2) don't have anaerobic zones.
I dont recommend pumps on timers but if someone wants to do it that way, it is a valid design and it works. If you asked me what intervals i recommended i would just say to try and make sure your fish tank volume turns over at least once an hour.
I was using cheap submersible magnetic drive pumps and they were failing every year or so. After researching online the general consensus seemed to be that the motor is stressed more during startup than if it ran constantly. (credit: travis huey). So i wanted to redesign my system to run constant on and no longer stop/start pumps to improve pump longevity. My experience since has confirmed
Over time, the inside of the vinyl tubing would gum up with solid matter and negatively affect the water flow to the grow beds. I dont know if/how much this affects pump parts but I decided that I wanted to move the pumps to where the fish tank water goes through some filtration before it gets to them.
So i redesigned my system for the fish tank to overflow into the grow beds (made of barrel halves), the barrel halves drain into the sump. Due to my space restrictions i had to use two different pumps, one to pump back into the fish tank and one to pump into the outer wood growbeds. Not ideal for power efficiency, but it worked.
The barrel halves had working bell siphons that allowed them to flood and drain even with constant water input. I couldnt get bell siphons to work consistently on the wood beds so they worked as constant flood.
This is the middle of august. Some cold weather plants and the squash have died. The peppers and tomatoes have stopped growing and are drooopy but they lived and came back strong in september. I planted some cucumber seeds in the barrel halves to see how they would do.
Ghost peppers. I didnt know any better but the green are not yet ripe. I didnt have the gonads to taste them but my coworkers said the red ones were great! I also got a few lb's of jalapeno peppers and a few dozen small roma tomatoes. They were almost as small as cherry tomatoes, not sure if that was due to low P-K or just a bad choice of tomatoes for texas climate. I'm going to try some types that figure to do better in texas in the future. I also ended up getting a couple of harvests of cucumbers before a hail storm pummeled the plants in october.
Cauliflower picture taken in December. The picture doesnt do it justice, The head is over a foot in diameter! And the plant is closing in on 5'... massive.
I also got some brussel's sprouts from the other grow bed. I never got a good broccoli harvest, though.
brian
