Hello Twilly,
It looks like there will probably be somewhere between 1/2 and 1 inch of water in the bottom all the time. I don't see a problem with that, as long as it doesn't fill faster than it can drain. With my limited experience with growing in sand (just got it running yesterday), I wouldn't want the dippers running 24/7. Right now I have the system timer set for 30 min on, and 2 hours off. But I expect to be adjust it as I go.
The system is filling faster than it can drain, so 30 min on floods it all the way to the top of the sand. It's dark right now, but I plan to fix that problem tomorrow. If adjusting the flow rate on the
pump doesn't work, I will split the feed line, insert a "T" connector and split the flow to the container in half. I will also look for that old fountain pump I have. It's much smaller, but I'm not sure how reliable (it's what I planed to use for this system anyway).
P.S. I'll post pics of it in a day or two. I germinated
seeds and placed them on top of the sand mix, then covered them with about 1/4 inch more of the sand mix. So there isn't really anything coming up yet. I'm also resurrecting another system I grew my peas in. I have 6 mini sweet pepper seedlings to place in it, and should have that done tomorrow as well.