My goal with these designs is to save energy by running a pump intermittently rather than 24/7 using an ebb&flow design, but the problem with ebb&flow is the regurgitation of solid fish waste and uneaten food.
I think these ideas would only be worth while if the system were small. With a large system the cost of circulating 24/7 would be applied to a much larger grow bed array. But for a small system where pennies count and the harvest is small, I think there are ways to make an ebb&flow work. Here are a couple ideas I've had.
An overflow would allow excess water to flow back to the fish tank.
While the pump is filling the settling tank a solenoid valve would hold the water in the grow beds and settling tank. A timer would turn the pump and the normally open solenoid valve off allowing the grow beds and settling tank to drain back to the fish tank.
This design is an improvement over the classic ebb&flow design because the settling tank allows for the water to be cleaned before returning to the fish tank.
Filtered drip lines from the reservoir would supply a constant water flow to the vertical tubes. If made of fiberglass reenforced weed cloth the water would be returned to the fish tank with plenty of aeration.
With proper filtration around the pump the system could be set up as simple as this.
The pump would be on a timer. The vertical media does not require constant flow.
The ebb&flow design above is a bit complicated. A design that has been working for two months can be seen at [The Perfect System]