Constant Water Spots on MB

xweaponx

So I'm beginning to feel like a failure at washing my car. I feel like I'm doing everything right, but I still end up with a bunch of water spots and they are beginning to be harder and harder to get out.
My 370z is Magnetic Black and I got it fully detailed (wash/buff/polish/wax) about a month ago. All the water spots disappeared. I wash my car on base where the water is supposedly "hard" and they have came back since.

I'll describe my washing process so you guys can state if I'm doing something wrong or something that may be causing these water spots.

First I was the car from top to bottom in straight lines and not circles. I wash the car in sections while keeping the whole car wet. I start with the roof. In-between washing each panel I hose off the sponge and spray it with high pressure to get the dirt off. Dip it in the soap again and start on the side panels on each side separately. Then I do the back of the car, the front, and the front bumper all separately. Pretty much every panel is done separately. While I am washing it I always keep the whole car wet. Then when I am completely done washing the whole car I spray it over once more to get all the excess, if any, soap off. Then I dry the horizontal surfaces first with microfiber towels in straight, smooth lines. I keep ending up with water spots no matter what.

I'm beginning to think it may be the mixture of soap to water I'm using somehow, even though I'm following the directions on the bottle.
It could also just be the water. I'm thinking about getting a filter for the hose.

Any suggestions or ideas on what could be causing these p.i.t.a spots?