Very Simple Gravity Style Auto Top Off System

[bbyatv]

I stole this idea from some place on the web and made some modifications so that it would work.

I have been using it for 5 weeks and it works perfectly.

Here is the general idea:



To build and use this gravity style auto top off system.

You will need the following materials:

1. A 4 litter wine bottle.
2. About 10 or so feet of air line tubing
3. Silicone sealant
4. An air line valve. (I used one that came with a power head for the venturi)
5. An 18" long piece of 1/2" PVC
6. An 1/2" PVC pipe cap
7. 8 inches of hard air line that will just squeeze inside the air line tubing


1. Take the wine bottle and drill 3 holes in the cap that are just a hair smaller that the air line you will use.
2. Feed/squeeze three pieces of air line tubing through the 3 holes in the cap
3. Make the tubing long is enough to reach the sump from where you will keep the wine bottle.
4. Cut 3 pieces of 2 inch long hard air line and force them up into the air line tubing from the inside of the cap.
(This will make a nice tight seal between the air line tubing and the cap as shown below)



5. Seal the 3 tubes and cap with some silicone sealant.
6. Add a piece of air line tubing that will reach the bottom of the bottle to the end of the hard air line that flows water to the sump.
6. Drill a hole in the PVC cap just big enough to force the end of the air line tubing through it.
7. Force a 2 inch piece of hard air line up into the air line tubing to create a tight fit with the cap.
(Just like the wine bottle cap)
8. Silicone the outside of the cap and tubing.
9. Cement the PVC cap on to the end of the 1/2" PVC tube.

To use the set up.

1. Mount the PVC tube above the sump in some way so that the tube is fixed and can not move. The end of the tube that is in the sump will determine the water level in the sump. So to adjust the water higher, move the tube up.
2. Fill the bottle with DI water.
3. Place the cap on the bottle and make sure it is tight.
4. Place the bottle so that it is higher than the sump. (Gravity works!)
5. Open the valve on the air line tubing.
6. Suck on the tubing that will flow the make up water down to the sump and get a siphon started.
7. Stick the end of the tubing you just started the siphon in into the sump area where the PVC tube is located. The end of this siphon line needs to be in the water. This prevents air from going back up the tube and killing the siphon.
8. Close the valve on the air line tubing.
9. Water will run from the bottle into the sump until the water level reaches the botom of the PVC tube and creates a hydaulic lock on the siphon.
10. When the water evaporates from your tank the water level in the sump will drop below the end of the PVC tube and allow air into the water bottle allowing the siphon to start again and water will flow into the sump until the level once again reaches the PVC tubing.

Here are some pics:







If you have any questions let me know.

Bruce