You welcome... me too. I was very shocked to see the test kit turn blue when on the bucket it claims < 0.00001 and even at < 0.01 I would accept that, but that's not what my test kit shows.
I'm going to check on Purigen and HydroCarbon down the road, unless someone can do the same test. Take 2 cups of RO/DI and put 2 tablespoons of carbon in a cup. Make sure the RO/DI water read 0 on TDS and undetectable on PO4 Salifert test kit before adding the carbon. Then wait 48 hours and then check.
Peace,
Jim