I`ve tried many things to remove water stains...razor blades etc.

I have a go-to I have used for years & it has never let me down.
I use a DA with an orange pad (not as aggressive as steel wool).
X-treme Clean has the "feel" of a very gritty polishing compound.

Rain‑X® X-treme Clean™ I prefer a small 4" or less orange pad