Are aquatic plants able to use Sodium hexametaphosphate as a phosphate source?

Sodium hexametaphosphate


The city water supply started adding 2.5 ppm Sodium hexametaphosphate { (NaPO3)6 } recently to help keep the pipes clean. They are selling the water to another city 25 miles away using pipes that aren't used often.

The manager at the city water supply told me that their incoming PO4 level is 0.19 ppm. Most of this is lowered to basically 0 ppm PO4 in one of the early processing steps. The finished total phosphate is 1.92 ppm. Ortho - finished is 0.53 ppm.

Normally my tap water phosphate level is from 0 to 0.2 ppm. It's 2-3+ ppm now. The other tap water parameters are:
-KH 25 ppm or 1.4 dKH
-GH 30 ppm or 1.7 dGH
-NO3 0 ppm

The water in my aquarium contains 3+ ppm PO4. I do weekly 50% water changes. here's the other parameters:
-pH 6.5 ± 0.1 (pH controller)
-KH 25 ppm or 1.4 dKH
-GH 30 ppm or 1.7 dGH
-NO3 5 to 10 ppm (it was lower but I made an adjustment)

Are aquatic plants able to use Sodium hexametaphosphate for a phosphate nutrient source? I'm not seeing any problems with the increased PO4 levels so far. I'm still dosing KH2PO4 normally. Should I cut back on my PO4 dosing?

 

Thanks Tom!

It is for corrosion control. Since I shower with this water, will my bodily corrosion be less?

That's good news. That molecule is such a "snow flake" shaped ionic bugger. I was wondering if there is a mechanism for the plants to break the bonds so that the plants can use P.