[jimbob1603]

I have lashed my diffuser pipe to the pilings/legs of the dock. Whether its down 1 foot or 3 feet is not an issue (I keep mine at 2 feet). But, it is critical that the entire diffuser be kept level. If it isn't level, air will not come out of the 'low' holes. The air will seek the path of least resistance (usually the holes closest to the water surface)

As an alternative to lashing it to the structure (which requires you to get wet to adjust the height), it can be hung from the dock. I made weights ( 10' rebar inside 1/2" pvc pipe; capped to keep the water out) and tied them to the diffuser pipe. Without some sort of weight, the diffuser will just float to the surface. This method allows you to adjust the diffuser pipe from the dock so you can make it level.

You can hook up 3 seperate diffusers for 3 seperate piers and run them off of one linear compressor. But, all 3 'circuits' must be level to each other; or else the low one probably won't bubble.

Be sure to test the system at whatever depth you expect it to operate. Don't set it up for 2 feet and expect it to run properly at 5 feet. Linear air compressors have a low pressure/high volume output and don't play nice at over 8 psi.

It takes surprisingly little water movement to keep ice from forming. If your system looks like a run-away Jacuzzi, you've got way too much air. Don't sweat it if a little crust builds up .... its the big stuff you need to worry about ... especially in spring.

It takes some work to build it and test it; but just think of how much cash you'll be saving because of low electrical bills. I'll be going up and turning the compressors on sometime in early December; even then they are on a thermostat and will run only below 35 deg..