What is best (and easiest)way to clean hard water spots from a window?

white vinegar and water adobe fo blue dawn dish soap and a dab of jet dry in a spray bottle

Try vinegar, it takes hard water spots off just about everything. Might take a few scrubs to get if off it is fairly thick.

Good idea. Thank you!

Our sprinkler system comes off ground water and is loaded with minerals. The spots can quickly make the window glass look "frosted". The best method we've found is using the cleaner for glass stove tops.

After the windows are spotless, go over them with a thin coating of lemon oil. It will not show and gives a sheeting effect for the water to run off. I think there are commercial products on the market that will do the same thing. Also, I use windshield washer fluid to wash my windows as it does the same thing - gives a sheeting effect so there are no water spots.

If they are really coasted, try warming the vinegar before applying it, not hot, just warm. Increasing the temperature even a bit will increase the rate of the reaction to make it come off faster.

We have well water that spots everything it touches then the afternoon sun bakes those spots. I have tried everything that i come across on cleaning including the above suggestions & the Only thing that works, on my windows & storm doors is Lime Out. Not Lime Away (or TLR) they didnt work for me. I used a scotch brite scrubber & put rain-x on after cleaned. I also poured it in a bathtub with hot water & soaked the screens. Thats what this Okie uses. Good Luck.