Before you go to the trouble putting chemicals through the AC plumbing
, I would check out the hoses. If you are in an area that has a lot of jelly fish
, one could have been sucked into the intake and stopped before getting to the raw water
strainer. If you open the raw water strainer do you get good water flow? If not then something is clogging the hose from the thru-hull to the strainer.
Next I would disconnect the hose from the strainer to the AC at the strainer and connect it to a hose from the dock
water supply. Turn on the pressure to the AC slowly and see if a lot of crud comes out the discharge thru-hull. If you still get poor flow with nearly full water pressure or get a lot of back pressure from the AC, then it is time to go to the chemicals.
Here is a link to my having a similar problem with my water cooled frig compressor
: Simple Repairs
Edited to correct the first sentence in the paragraph above to read, "Next I would disconnect the hose from the pump
to the AC at the pump and ...."