Good Morning Chuck,
Start up Gospel correct.
Secondly, the intake filter is ok as long as it is clean. To clean it, use a compressor and blow it out from the inside out. If no compressor available, lightly use some sand paper on the outside and then bang the dust off.
Lastly, the increase pressure may be due to some water still in your airline. If the check valve has failed, which will occur due the hardening of the o-ring inside that check valve, water will fill the air tubing.
Yes, you are receiving bubbles but that is because the compressor is having to work harder to push that air through the tubing. Think about looking at the cross section of the tubing. You have a hole and the bottom half of that hole is filled with water. The top half is where the air is being pushed to the diffuser. So, the area is smaller requiring more pressure to push the air thorugh.
Another example is if you take a McDonalds Drinking Straw and a stirrer straw. It takes more pressure to blow air through that smaller stirrer straw than it does through the drinking straw.
If left alone, eventually that water will be pushed out or evaporated as the air by-passes.
The other option is:
1. Bring the diffuser to shore
2. Disconnect the diffuser from the tubing
3. Remove all the water from the air tubing
4. Reconnect the diffuser
5. Turn the system back on
6. Re-deploy the diffuser with the system on
While you have the diffuser back on shore, that would be a great time to replace the blue check valve.
Good Luck...This is the only thing I can think of creating back pressure unless you have a kinked line somewhere.
