Hard Water, Tough Cookies

I'm a little frustrated that my algae is about as bad as it has been in a while. I probably shouldn't complain, because I can remember the whole situation being a lot worse, but I'm not used to having my amazon and temple leaves caked with what I only know to call green spot algae. It might be something else, but it is creating a hard, dark green coating on the leaves more aggressively that I've seen in a while. My phosphates are still sky high, so maybe they aren't mixing well with the calcium carbonate.

Speaking of which, I managed to find a SAWS report on the tap water I'm using, and sure enough, it is quite hard. Total hardness is listed on average at 233 ppm, and the total dissolved solids (TDS) is nearly 300 ppm! Curiously, it lists the pH range from 7.5-8.0; while I've noticed it to be fairly consistently 8.0, I observe it coming out of the tap at 7.0 due to high concentrations of what is presumably dissolved CO2 (what else changed my drop checker?).

Anyway, all of this, combined with the return of the white film on the amazon (although, suspiciously, it is not as easy to wipe off) prompted me to post on Aquatic Plant Central to see if other hard-water victims had any remedies. I will patiently wait for replies/suggestions.