I am very new to this. So bare with me and my dumb questions. Flood and drain system. I have a 90 gallon fish pond that I am pumping into a 17” x 33” grow bed. It is taking 5 min. to fill and drain (12 times an hour). Is this ok and do I let it run continuously?
Yep how ever fast it does it, is how fast it does it since to change it probably requires messing with flow rates and plumbing sizes. The more flow you can filter through the grow beds the better the water quality for the fish tank.
If you have a siphon then yes generally you just let the pump run continuously.