I looked at my outdoor AC unit yesterday and it looks like the coils are starting to deteriorate. I looked online and it looks like it's some kind of corrosion. Is this fixable at this point? Or is this unit shot? Also we have pretty hard water here, is that what is causing this? From reading online it sounds like minerals in the water can cause this.
Your coil is in horrible shape. If it still works it can be cleaned and the bent fins straightened. The fins radiate heat from the tubes that carry the super heated Freon in this case. Salt air can also cause this. If the unit still works a good non acid foaming cleaner should be sprayed into the fins (after the bent ones are straightened). There are plastic fin combs that help to do this and can be purchased online, get a full set so you will have the correct combs per inch. I think my set goes from 8/" to 16/" or something like that. The non acid foaming coil cleaner may need to be applied 3 or 4 times and flushed with water until all the dirt is out and you may be able to see through the coil. Getting this fixed now may give you a few more years life and a lower power bill. Good luck.