Need help. Diy gravity fed ATO

shiftline · #1 03-31-2016, 06:34 AM

I would just use a float valve to open and close the valve as needed. Simple as it gets

mike31154 · #2 03-31-2016, 02:49 PM

Thread title contains 'gravity' but you mention 'air' in your first post. True gravity feed would have the top up reservoir above the vessel you are topping off. Head pressure would then feed the liquid through a simple mechanical valve into the tank or sump.

If you're talking about pressurizing the top off reservoir with air which will push the water through the tubing, the process is similar, except for the extra tubing for air into the reservoir. That is the set up I've been using successfully for many years. 7 gallon glass carboy, timer, air pump, tubing, mechanical float valve. The mechanical valve is one made for furnace humidifier trays available for about $10 at most hardware retailers. My timer runs a few minutes every hour to keep the carboy under pressure. I modified a rubber stopper with 2 holes, one for air in & one for water out to the tank. Rigid air lines go through the stopper & are connected to flexible tubing. I used scrap acrylic to fashion a bracket that holds the mechanical valve in position on the rim of my display. Nylon screws hold the bracket securely. I drilled & tapped holes in the bracket for the nylon screws.

Glass carboy keeps my 77 gallon topped up for about 7 days.

'Wait" brand mechanical valve. I cut two chambers off this later to shorten it making less of a footprint in the display. Still works fine.

proudnewbie · #3 03-31-2016, 03:33 PM

So not quite what I was talking about. This will be a true gravity feed ATO as the reservoir will sit above the tank, but will have two lines going into the water. one will be the water line and one will be the air line, both of with will go into the display tank. The "Air line" works as your minimum tank volume as it creates a small vacuum when plugged with water. The water line only runs when air flows into the top of the jug via the air line. so when the water drops below the "air line" the water line starts to flow until the air line gets plugged with water.
Think of the old cup in water trick where you fill a cup in a tub and flip the cup. The water can be raised above the body of water. If you add an air hole to the top of the cup and cover it, same thing happens. But then you open the air hole the water looses the vacuum and flows through.
so here's a basic drawing of what im trying to do.... I've followed lots of posts and know it works (tested in my laundry tub with no modifications) but don't know how to attach the air lines to the tap.
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proudnewbie · #4 03-31-2016, 03:47 PM

So to sum up what I need is something that can attach to the bottom of the tap and connect to a hose. I've seen rubber ones bot I don't think the rubber is aquarium safe.

I could also replace the tap altogether with a something to a ribbed hose connection (excuse my poor plumbing lingo)
something like this

https://www.homedepot.ca/en/home/p.p...000123290.html
But I don't want to loose the tap for easy shut off.

proudnewbie · #5 03-31-2016, 06:46 PM

Ended up going with something similar to the second picture. It curves though. I'm going to add some silicone to make sure all is snug, and might post it into the DIY section for others. So far it looks like this is going to cost me a whopping $17 plus tax for the whole ATO. Not too shabby