Evaporative Water Coolers - Removing mineral deposits

Well, time to button up the garage cooler for the winter. I'm having a heck of a time removing the mineral deposits this time though. It was manually purged every 12 hrs or so of running this year and it did seem to keep the buildup on the pads down, but the ones on the fins are real bad. Didn't seem to be this hard to remove last year even when I wasn't purging. Did a good cleanup on it about 1/2 way though this season, when I changed pads due to mold (had the water level too high I think)

Normal scraping and brushing got the big buildups but really isn't doing anything to the harder areas.

Tried draining the pan and putting 2 gal or vinegar in, let it run pump only for 2 days. Not much diff. Added some CLR and ran it as well as hand brushing it on several times a day. Not much help.

Finally tried a little metal prep (dilute phosphoric acid basically) applied by brush..well it softened the deposits as well as the paint....lol.

So..is there a magic solution? Or should I just get neanderthal on it with putty knives and wire brushes and repaint the cabinet after all the paint gets damaged?


Oh...and do those inline mineral filters really do anything...or are they just smoke and mirrors?

I know its been a while...but I'm getting back to sealing this thing up for the season. Its stayed pretty nice, but now I'm getting cold from the thing..so time to wrap it up.

Any suggestions on the deposit removal and/or prevention for next season?

Sammy...where you hiding????