Hi,
I have one of these softeners,
http://www.espressoparts.com/product/V_104

and was curious how often I need to recharge it? Also what type of salt should I use? Is kosher salt OK?

Thanks,
Joe

Commercial use?
1-2-3 months depends on your water hardness
home use?
4-6 months depends on your water hardness
takes 20-30 minutes 2 pound of rock salt
it is worth doing it more often then have repairs done later

Not to be rude, but you need to recharge when you have saturated the capacity of the softener resin to reduce the harness of your water. You need to get yourself some test strips or a harness test kit so that you can monitor your water and know when to recharge. The time period is a function of your input water (the input harness) and the amount of water that you soften (run through the resin).

I use the following strips and find them to be cheap and accurate enough for me to monitor my softener.

http://www.diywatertesting.com/sofchekx3.html

These have a better range (finer and clearer differences) compared to some of the other strips that I have tried, and they are the cheapest that I have found.

Good luck,
Mark

Do a Google Product search for "TDS Meter." these are very handy and very affordable. There are plenty up for auction for under $20 at you know where....

This one (link to eBay) is interesting. It uses John Guest fittings and can be placed inline for real-time monitoring. For only $25 shipped, with the proper fittings (you can specify what size you want) it could be placed on the suction line before the pump. COOL! Another digital add-on!

I have a calcium hardness test kit I use for my pool. I just tested my boiler water and my hardness is 10ppm. Its a titratable test so its very accurate but I'm not sure it applies in this application. Any ideas?