Backyard Aquaponics
A place to discuss aquaponics

Great Scotty another project I have to add to my list of projects.

I did my drain as suggested. I used a stand pipe with four small holes drilled on the bottom. With the 900 gph pump it took 4 minutes to fill the grow bed and it took 37 minutes to drain. What is the suggested time to fill and drain a grow bed?

If you're using a regular 15 minute interval timer then it sounds like the 900 GPH pump is overkill for the moment. If it is a 15 minute timer it's full in 4 and overflowing for another 11 minutes, then draining for 37. A gravel bed uses something like 40% of the volume for water, if you can estimate the volumes then you might tell what kind of FT water turnover you're getting right now in an hour (trying to turn over the FT at least once per hour). Or if you like the way it is now you can always keep it as it is. Or use a smaller pump and use less electricity. With timers since the cheapest ones use 15 minute intervals the usual intervals are 15 minutes on and 45 minutes off. As long as you're empty within that 45 the draining is OK.

It doesn't need to be very energetic-seeming, media bed systems can seem pretty slack once they are running and you just feed the fish and watch the plants grow after that. Take a look at zsazsa's videos for example, just a nice trickling water sound in the greenhouse.