Flood and drainage timing?

[Lawrence Creech]

I am a newbie and was just curious about the timing between a full grow bed and fully drained bed? Is it ba to have them too quick or too slow? Right now I have a 25 gallon GB that fills in near 10 mins and drains in near 4 mins.

Let me know what you know.

Thanks.

[Jonathan Kadish NYC AA Chair]

The scientific community has only focused on DWC  from what I have seen. It would be great to know the best practices for media beds based on test like this. Thanks for sharing your results.

Community AP said:

If it is working for you then that is great.  My point was less flooding equals better development. I have two fast flows for herbs and testing but my slow fill on 35 minutes produces better results, even with peppers.

[Jon Parr]

Yep. Roots, worms, and bacteria all need water (and the nutes contained therein) and air (oxygen), and there is a huge allowance and overlap for different growing styles and climes. If you are drying out between floods, then you shorten the flood intervals. If you are getting stinky water or drowning plants, then you should lengthen the flood interval (or speed up the drain, or add air to the bed, etc). Fish usually appreciate constant pumping, and plants appreciate longer intervals (usually), so any combination of timing that keeps it all happy is fine (which of course is 15 minutes fill, 4 minutes drain, and 41 minutes idle, duh)

[TCLynx]

I've run constant pumping with siphon flood and drain and guess what, it worked just fine.

I've also run constant flow/flood, and that worked fine until the banana completely blocked the bed with roots causing overflow issues.

I've run timed flood and drain with 15 minute pumping and 45 minute off, that worked too.

I've run timed flood and drain with shorter fill times and longer dry times using the indexing valves so that I could flood beds in sequence and keep almost constant return flow going to the fish tank but giving the beds more dry time, this works really well.

All of the above was with media beds of course and I'm rather partial to them for backyard growing.  I actually like a combo of methods when I might have a few beds getting constant flood/flow to grow things like water plants (watercress and water chestnuts) while I have constant flow to the fish tank and then I can alternate flow to grow beds and towers using automated valves and indexing valves to give more air time to the plants while still providing constant filtration and at the same time minimizing water level fluctuation issues.