On 3/26/2012 12:24 PM, KenK wrote:
Perhaps someone can make a suggestion.

I bought a new evaporative cooler last spring. (An evaporative cooler
replaces an A/C in dry weather and costs much less to run. It runs water
though pads, which have air sucked through them and blown into the
building. They work quit well.)

This spring, as usual, I prepared it for a summer's use. Replaced pads,
lubricated blower, cleaned the interior, and checked it out. For the
first time I found a inch or more coat of calcium from my hard-water well
in the bottom of the reservoir (about 3 x 3'). Never happened before in
some 30 previous years. Granular on top and a 1/4 to 1/2" of solid below.
The problem is removing the solid. Scraping will take many many hours and
will surely damage the paint. I'm currently trying a generous amount of
Lime-a-way (active ingedient unlisted) in an inch or so of water on it.
Helps, after a couple of days, but not very much. I tried adding some
toilet bowl cleaner (20% hydrochloric acid) earlier this morning but so
far little help. I don't want to damage the baked-on enamel paint if I
can help it. Swimming pool acid sounds rather drastic to me.

A cooler book I have suggests a tile and tub cleaner. Those I looked at
at Walmart didn't say much if anything about removing calcium so I will
use the TB cleaner instead - this brand (The Works) works VERY well on my
toilet the past few years.

Evidently my well water has suddenly this past year become much much
'harder'.

I have plans for avoiding this problem in the future but first I need to
remove what's there now.

TIA



I always used city water so my deposits may not have been as bad as yours.

But, looking on the internet looks like you might try:

Vinegar solution (most likely garden vinegar) or

Lime Away or CLR.