i am having a hard time keep my house cool with my evaporative-coolers they are only 5 years old pretty much new to me. i have not had this problem before but i thing it my cooling pads. i have been lazy and have not clean them out on a weekly bases. had just clean them a few days ago and notice that have a lot of calcium build up on my pads and on the out side of the cooler. it doe not get above 20% humity( i live in the high desert of California).what can i do to clean the pads more with out having to buy new pad ($30 to $60) they are foam pads. or should i go to shredded aspen or wood shredded pads, i try to aoved them do to me having allergys.