How long should I waiting roughly. I waited like 2 minutes..
Compressors do not move a lot of cubic feet per minute. You might not be waiting long enough or you might have air leaking out somewhere
As JamesW mentions above. There may not be enough volume.
Please make sure main drain valve is open. Then, it is suggested that you have everything closed off, plugged, valve turned so only air is heading down to the main drain. If you can post pictures of the plumbing that would be great. You only want air moving towards the main drain. You might have an air leak coming out, but my guess is the 3 gallon tank now sending out a burst of air is not enough volume to move water and/or create a lot of bubbles at the main drain. When you send air down to the main drain, how quickly does that tank dump and start filling up again?
Question on removing water and pushing air through system
Take a look @ Post # 8. Maybe when the tank dumps, you could allow it to fill up and then once you open up the tank open the valve again. Or as Pool Tool states that he starts with fairly low pressure until most of the water is removed and then he increases pressure to get every bit out. He does not mention main drain, but you can give this a try.
Notes that I had acquired prior to Cyclone Purchase
This is all the information that I gathered over the months.
• Blowing out an 8 foot deep Main Drain line only takes about 3.5 - 4 psi.
• The motor has to be large enough to keep around 15-20 psi in the tank so you can keep a constant 8-10 psi going into the lines.
• Do not over pressurize the lines. 5 to 10 psi is sufficient.
2 skimmers at 100 feet of 2 inch PVC..............4 cubic feet
1 main drain at 100 feet of 2 inch PVC.............2 cubic feet
1 Polaris line at 100 feet of 2 inch PVC............2 cubic feet
1 vacuum line at 100 feet of 2 inch PVC..........2 cubic feet
2 Return lines at 100 feet of 2 inch PVC..........4 cubic feet
3 foot diameter sand filter...........................14 cubic feet.
Miscellaneous.............................................2 cubic feet.
________________________________________________
Total......................................................3 0 cubic feet
Word of caution when blowing lines with a compressor. They don't usually blow enough volume to displace all the water. It may only form a tunnel in the pipe.. It can blow a hole in flex pipe. Line blowing is best done with a
high volume of low pressure air. Compressors generate low volumes of high pressure.
Please make sure that you have your compressor on low pressure to create more volume. Maybe check the specifications on your air compressor to determine if this is even possible.