gravity ato via air pressure - anyone?

[Origami]

Thanks, Matt. From the explanation, it looks like the J-tube is used to hold prime on the siphon so you don't have to restart it with each reservoir refill.

[lnevo]

Ahh, pretty cool. How do you prime the siphon though?

[Origami]

Ahh, pretty cool. How do you prime the siphon though?

I suspect by either adding air pressure pressure to the reservoir through the air tube or some other access, or by drawing water into the fill tube with a plastic tube or something.

 

In some ways, this is similar to a drip-doser that I used years ago that was built around a soda bottle (similar to this one on RC), but with air vent used to sense the level of the water in the tank and with the addition of a precisely set j-tube.

[ronl]

I can post some pics tonight when i get home of the two acrylic ones that I built. I still have them, but I scrapped the 5 1/2 gal glass tank version a few years ago.

 

The vacuum is started by blowing into the tube that sets the water level until water flows through the feed tube and there is no air in the feed tube. As long as the rigid tube that goes to the bottom of the inside of the container remains submerged, the system will retain the vacuum.

 

When the water level in the sump drops, the bottom of the tube that sets the water level will become exposed to air, which then causes the ATO to fill the sump with water from the container. Once it fills the sump enough to cover the bottom of the tube, the water will stop filling the sump.

 

There is a clamp on the feed line to keep the water from flowing when you remove the cap to refill the container. This makes it so you don't have to re-prime it each time you refill the container. This works as long as you refill before the bottom of the inside rigid tube is exposed. If you let it run dry then you need to re-prime after refilling.

 

The J-tube on the end of the fill line is to prevent micro bubbles from getting into that tube. As I mentioned, that tube must be purged of air for the ATO to work. If enough air bubbles are allowed to accumulate in that tube, it will eventually break the siphon and won't fill the sump.

 

A larger diameter air tube will keep a narrower range of water level in the sump because the top of the water won't cling to the tube as long as it will with a smaller diameter tube. That is also the reason that the end of the air tube is angled in the Aqualan product.

 

As I mentioned, my only mishaps were overfilling the container because I wasn't paying attention. Also, trying to prime it by blowing into the air tube before I put the cap back on after refilling. That sprayed water inside the stand on my ballasts and other electrical items. But those are my fault, not the system's fault.

 

I think that answered all of the questions so far.

 

Thanks,

Ron (ronl), not to be confused with roni

[matt]

Ron, this great detail. Please do post some pics so we can admire your work and lean from it

[ronl]

Matt, my acrylic work leaves a lot to be desired. Think Weld-On 16 with ugly seams with bubbles and a thick bead on the inside like caulk to ensure it is sealed. But hey, neither of them ever leaked. They aren't pretty, but they were in the stand where they weren't seen, so I didn't care what they looked like. :-)

 

Those that frown upon this type of ATO argue that every time the top off is activated, some of the sump water goes up the air tube into the container; thereby reducing the salinity in the tank as it is replaced with fresh water. In my experience, the amount of saltwater that gets sucked into the container is very minimal, so I didn't see it as a big problem. I figured the salinity was more stable than when manually topping off.

[s2nhle]

I can post some pics tonight when i get home of the two acrylic ones that I built. I still have them, but I scrapped the 5 1/2 gal glass tank version a few years ago.

 

The vacuum is started by blowing into the tube that sets the water level until water flows through the feed tube and there is no air in the feed tube. As long as the rigid tube that goes to the bottom of the inside of the container remains submerged, the system will retain the vacuum.

 

When the water level in the sump drops, the bottom of the tube that sets the water level will become exposed to air, which then causes the ATO to fill the sump with water from the container. Once it fills the sump enough to cover the bottom of the tube, the water will stop filling the sump.

 

There is a clamp on the feed line to keep the water from flowing when you remove the cap to refill the container. This makes it so you don't have to re-prime it each time you refill the container. This works as long as you refill before the bottom of the inside rigid tube is exposed. If you let it run dry then you need to re-prime after refilling.

 

The J-tube on the end of the fill line is to prevent micro bubbles from getting into that tube. As I mentioned, that tube must be purged of air for the ATO to work. If enough air bubbles are allowed to accumulate in that tube, it will eventually break the siphon and won't fill the sump.

 

A larger diameter air tube will keep a narrower range of water level in the sump because the top of the water won't cling to the tube as long as it will with a smaller diameter tube. That is also the reason that the end of the air tube is angled in the Aqualan product.

 

As I mentioned, my only mishaps were overfilling the container because I wasn't paying attention. Also, trying to prime it by blowing into the air tube before I put the cap back on after refilling. That sprayed water inside the stand on my ballasts and other electrical items. But those are my fault, not the system's fault.

 

I think that answered all of the questions so far.

 

Thanks,

Ron (ronl), not to be confused with roni

Thank you very much for taking your time explain this system and sorry for mis-spelling your name.

[ronl]

No problem on the mid-spelling. ronl and roni are hard to tell apart on the screen, especially on a phone. I know there is someone on the board with username roni, so I just wanted to try to avoid any confusion. I know when I see a post from roni I have to look twice to make sure it is not my username.

[ronl]

Ok, let's see if I can remember how to post pics. 

 

The first two pics are of the 6 gal ATO.  In the second pic from the side you can see the rigid tube inside the container that goes down to about 1/4" from the bottom.  You can also see the melted rigid tubing that serves as the J tube.

 

The second two pics are of the 1.5 gal ATO.  The rigid tube inside is dirty, so it is easier to see than the one in the larger ATO.

 

You can also see the tube clamps and the bracket that I made to hold the tubes to the side of the sump.  The height of the tube opening on the air line (tube without the J) determines the level of the water in the sump.  I used a PVC fitting with a rubber cap to be able to open the top for refilling.  The rubber cap helps to keep everything airtight, which is required for this device to work.  The screw on cap with rubber seal that is used on the Aqualan NURCE is nicer because it would be easier to get on and off and it provides a bigger opening.  The plumbing part that I used did not come in a larger size, so that was the largest opening I could do.

[ronl]

One other thing, these have to sit on platforms because the water level in the ATO container has to be higher than the water level in the sump for gravity to do its thing.  So I made the platforms high enough so that the bottom of the ATO was slightly higher than the desired water level in the sump.

Edited September 27, 2013 by ronl

[matt]

Ron, thanks a bunch for taking pics. Is there a reason these are built to be taller vs wider? Would performance be impacted if they were long low rectangles instead? Also, are there any specific considerations for choosing tubing sizes and rigidity for air and water lines? Thx!

[nova423]

has anyone had success, or failed, using this type of ato? contemplating something along these lines for 5.5g nano that will run sumpless. Without partitioning off a low water level area, many ato switches (not $200) could prove not sensitive enough to maintain salinity when installed in the main display.

 

if you aren't familiar with this approach, see here:

 

http://reefbuilders.com/2009/05/26/diy-tea-jar-auto-topoff/

 

http://www.reefcentral.com/forums/showpost.php?p=14350717&postcount=16

This is great, I literally bought a water bottle today with this in mind for my 10g. Following!

[ronl]

Ron, thanks a bunch for taking pics. Is there a reason these are built to be taller vs wider? Would performance be impacted if they were long low rectangles instead? Also, are there any specific considerations for choosing tubing sizes and rigidity for air and water lines? Thx!

Taller or wider will both work. These two were built to fit exactly in the space I had inside my stands. So I had a limited footprint and the only other way to go was up.

 

My original ATO was a standard 5 1/2 gal glass tank, so that one was wider and shorter. Only reason I built the bigger acrylic one was because the 5 1/2 gal tank was a half an inch too wide to fit where I needed it in the stand.

 

Rigid tubing should be used for the tube inside the container. The two external tubes are flexible so you can position them in the sump and so you can pull the air line out to blow in it to create the vacuum. It also allows you to clamp the tube when refilling.

 

Ultimately, the most important thing is that the system is airtight. Otherwise the entire container will drain into the sump.

Edited September 27, 2013 by ronl

[matt]

Ron, and you really do need the vertical supply tube inside the box right? A bottom mounted drain would have too much gravity on its side despite the vacuum...correct?

[ronl]

I never tried one with a bottom mounted drain, so I don't know. I was trying to replicate the function of the Aqualan NURCE, so I followed that design as close as I could.

 

I don't know for sure, but I would think the bottom mounted drain might self prime. I didn't read the link of the person that used that design. Although I imagine the entire ATO container would need to sit above the top rim of the sump rather that just above the sump water level with the design that I used.

Edited September 27, 2013 by ronl

[ronl]

After reading the two links with the bottom drain designs, if I had the space to raise the ATO containers completely above the rim of the sump, I would have probably tried the bottom drain design. Looks like it saves you from having to blow into the air tube to prime the system to start the siphon. As both of those links also pointed out, having an airtight system is of utmost importance.