would this work to maintain a water level?

would this setup work for an automated reservoir top-off? I figure as the plant drinks h2o, the line will draw h2o to keep the pressure consistent, or would the syphon continue once started and the reservoir completely overflow?

I think it would continue but why the concern about automating it? Plants drink water and how much they drink is an indication you need to be aware of of how they are doing. I adjust nutes when I top off water and make it part of a daily maintenance schedule.

Umm well I do that on the daily but would like to be able to leave the system unattended for a few days. Probably not much of a possibility, it will be so close to harvest when I have to leave them that I will probably be flushing anyways.

I don't believe your setup will work as designed, it would probably just keep draining. If you want to do a gravity fed top off without floats/valves, you'd probably need to design something similar to a water cooler or pet water top-off bowl, where as the water level drops air is allowed into the system until the level rises again.

I modified your attachment to demonstrate. Basically, one end of your tube/hose is attached to the top-off reservoir, and the other end is attached so that the bottom of the tube is even with the level you want to maintain. As water is used the level drops below the end of the hose, which allows air into the top-off reservoir, which allows water to flow until the level goes above the end of the tube and no more air can get in. The top-off reservoir has to be air-tight. I've done this using gallon jugs in the past.

yep that sucks. I have a local sitter when I have to go out of town ha ha luck.

ok thanks, yeah I get that with the air-tight feeder reservoir, it would definitely work that way.

well if I do leave town I'll just top off with as much fresh water as I can and peace and try to get back in a day or two haha because I really add back almost a 1/2 a res of fresh water a day. damn 10 gal reservoirs...

ok I thought about this today and I do have the solution.

you need an air tight container on the top like a coke bottle. 90 off that coke bottle to just below the normal water level I'n your tank. the air tightness of the coke bottle will keep it from over flowing if the water will not allow air inside the tube. like this. I would build a stand for it from pvc. and just poke a hole in the top of a the bottle cap and use glue and plumbers putty to get a good seal around a 3/4 or 1/2 inch hose or pvc end.


like so




remember air tight water tight light tight