tastydog
New member
The challenge:
Design an automatic top off for a 5.5 gallon tank that has no sump without adding ANY switches, floats or anything intrusive into the tank. Also, be able to build this for less than 10 bucks with a goal of less than $5. (The tank is a closed system with no sump.)
Background:
In the dead of summer the tank needs a maximum of around a quarter gallon of water a day. I do not plan to have this connected to my RO/DI reservoir because this tank sits on a shelf in the bedroom and the RO/DI reservoir is above the hot water heater in a closet located in the living room. (That reservoir is what tops off my 90 gallon and gives me quick access to water for water changes.) So, my idea is to have a jug that is between 1 and 5 gallons. I could put this jug in my closet and run lines down to the tank non-obtrusively. I just want to find a container around the house or garage.
So, my idea:
I have an idea that I didn't full test, it seems like it will be difficult to make it work properly from my preliminary tests. However, I didn't try really hard to set things up perfectly as it would be when it would be finished. I just wanted a proof of concept. It may be that I need to be more rigorous in my setup in order to obtain proof of concept.
My idea is similar to the cat or dog bowls you see at any pet store. You know the ones that have an inverted bottle or jug on the top of them down to a dish that is submerged in water. When enough water is removed it exposes the outlet and air is able to get in. When enough water has drained, the hole is "plugged" with water and it is stable. The key to these is having a non-flexible container to hold the water.
What I did was take a glass bottle with a plastic lid and drill two holes in it. One of the lines was placed through the first hole and only inserted about 1/2" in. The other line was inserted one inch in and then I added a hard non-flexible 1/4" tube that extended to the bottom of the glass container. (This will actually be the top of the unit and this line is the air intake.)
Then, the bottle is filled with water and placed cap down well above the tank. I drilled two holes in the plastic part of the top for the tank for each line. One line is inserted a least a few inches into the water. The other line is only inserted so that it is barely submerged at the desired water line. At this point since both lines are submerged no water escapes the bottle and nothing happens. Once the water evaporates enough, just like the dog/cat bowl, air is let into the bottle letting water flow out the other tube until the line is once again completely submerged. Or at least that is what is supposed to happen. I only really tested this thing once last summer and it didn't seem to work as expected.
The problems I encountered
When I first put the lines in the water and then turned the bottle upside down it sucked water 3/4 of the way up into the air intake line. When I pulled the air intake line out far enough so that it was barely above the water line, the water in the air intake line first had to be sucked into the bottle before air was allowed in. Basically the pressure of the water wanting to come down the water line was enough to not only fill the air intake but also enough to pull the water through the line when the line wasn't submerged. So, this created a strange issue that when the line was just barely out of the water it kind of cycled sucking water into the air line and then letting the same amount of water in the tank until the air line was full of water and then nothing seemed to happen until I pulled the air intake far enough out. Then, it seemed to work but was not very convinced of how well it would work in practice. Then, my seal broke around the lines going into the cap and air was leaking in regardless. This was the end of this test and I was frustrated enough that I just gave up. Fall set in and the tank was now manageable with manual additions of top off water. Now, summer is knocking at the door and am feeling the pressure to revisit this problem and find a solution.
Possible solutions
I have concluded a few things about this design but I need either some help, clarification, someone to tell me it won't work, someone to correct me on my conclusions and or design or another idea completely. (Maybe a combination of them even
. ) One conclusion is that the size of the air intake line should probably be large enough and the vertical run on the line long enough that the pressure of the reservoir is not sufficient to "plug" the line. So, when the tank level falls enough, the water simply falls out of the air intake and air is let into the reservoir. The other idea would be to cut the air take line on an angle and possibly even run a smaller line inside the air intake line for a foot or so and have it exit on the high side of the angled end. This way air is allowed in regardless if the small line fills with water or not because once the larger line is completely exposed the water will suck through the small line into the larger line and then the larger line will have a way to let the lodged water drain and the air allowed into the reservoir. (This idea comes from the glass oil dispensers I use in the kitchen when cooking. Without the small line running in air would have a very hard time getting in, even though it would seem that the small tube would plug just like the large tube, it doesn't.)
Enough already!
Okay, so this turned out be a much longer post than I had anticipated and I am sure it will not be read by many because of its length. However, I hope that someone will be able to help me understand how to make this idea work properly or at least offer some insight on to possible design solutions. Maybe someone has already tackled this problem on their own and has a solution for me.
Regardless of what happens I want to thank you for your time if you have made it this far. It was much more difficult to explain this than I had anticipated. I have attached a picture for visual aid as the explanation alone may be confusing.
Brandon
Design an automatic top off for a 5.5 gallon tank that has no sump without adding ANY switches, floats or anything intrusive into the tank. Also, be able to build this for less than 10 bucks with a goal of less than $5. (The tank is a closed system with no sump.)
Background:
In the dead of summer the tank needs a maximum of around a quarter gallon of water a day. I do not plan to have this connected to my RO/DI reservoir because this tank sits on a shelf in the bedroom and the RO/DI reservoir is above the hot water heater in a closet located in the living room. (That reservoir is what tops off my 90 gallon and gives me quick access to water for water changes.) So, my idea is to have a jug that is between 1 and 5 gallons. I could put this jug in my closet and run lines down to the tank non-obtrusively. I just want to find a container around the house or garage.
So, my idea:
I have an idea that I didn't full test, it seems like it will be difficult to make it work properly from my preliminary tests. However, I didn't try really hard to set things up perfectly as it would be when it would be finished. I just wanted a proof of concept. It may be that I need to be more rigorous in my setup in order to obtain proof of concept.
My idea is similar to the cat or dog bowls you see at any pet store. You know the ones that have an inverted bottle or jug on the top of them down to a dish that is submerged in water. When enough water is removed it exposes the outlet and air is able to get in. When enough water has drained, the hole is "plugged" with water and it is stable. The key to these is having a non-flexible container to hold the water.
What I did was take a glass bottle with a plastic lid and drill two holes in it. One of the lines was placed through the first hole and only inserted about 1/2" in. The other line was inserted one inch in and then I added a hard non-flexible 1/4" tube that extended to the bottom of the glass container. (This will actually be the top of the unit and this line is the air intake.)
Then, the bottle is filled with water and placed cap down well above the tank. I drilled two holes in the plastic part of the top for the tank for each line. One line is inserted a least a few inches into the water. The other line is only inserted so that it is barely submerged at the desired water line. At this point since both lines are submerged no water escapes the bottle and nothing happens. Once the water evaporates enough, just like the dog/cat bowl, air is let into the bottle letting water flow out the other tube until the line is once again completely submerged. Or at least that is what is supposed to happen. I only really tested this thing once last summer and it didn't seem to work as expected.
The problems I encountered
When I first put the lines in the water and then turned the bottle upside down it sucked water 3/4 of the way up into the air intake line. When I pulled the air intake line out far enough so that it was barely above the water line, the water in the air intake line first had to be sucked into the bottle before air was allowed in. Basically the pressure of the water wanting to come down the water line was enough to not only fill the air intake but also enough to pull the water through the line when the line wasn't submerged. So, this created a strange issue that when the line was just barely out of the water it kind of cycled sucking water into the air line and then letting the same amount of water in the tank until the air line was full of water and then nothing seemed to happen until I pulled the air intake far enough out. Then, it seemed to work but was not very convinced of how well it would work in practice. Then, my seal broke around the lines going into the cap and air was leaking in regardless. This was the end of this test and I was frustrated enough that I just gave up. Fall set in and the tank was now manageable with manual additions of top off water. Now, summer is knocking at the door and am feeling the pressure to revisit this problem and find a solution.
Possible solutions
I have concluded a few things about this design but I need either some help, clarification, someone to tell me it won't work, someone to correct me on my conclusions and or design or another idea completely. (Maybe a combination of them even
. ) One conclusion is that the size of the air intake line should probably be large enough and the vertical run on the line long enough that the pressure of the reservoir is not sufficient to "plug" the line. So, when the tank level falls enough, the water simply falls out of the air intake and air is let into the reservoir. The other idea would be to cut the air take line on an angle and possibly even run a smaller line inside the air intake line for a foot or so and have it exit on the high side of the angled end. This way air is allowed in regardless if the small line fills with water or not because once the larger line is completely exposed the water will suck through the small line into the larger line and then the larger line will have a way to let the lodged water drain and the air allowed into the reservoir. (This idea comes from the glass oil dispensers I use in the kitchen when cooking. Without the small line running in air would have a very hard time getting in, even though it would seem that the small tube would plug just like the large tube, it doesn't.)Enough already!
Okay, so this turned out be a much longer post than I had anticipated and I am sure it will not be read by many because of its length. However, I hope that someone will be able to help me understand how to make this idea work properly or at least offer some insight on to possible design solutions. Maybe someone has already tackled this problem on their own and has a solution for me.
Regardless of what happens I want to thank you for your time if you have made it this far. It was much more difficult to explain this than I had anticipated. I have attached a picture for visual aid as the explanation alone may be confusing.
Brandon
