Thats in the acidic range bud. Ph ranges from 1-14...pure water is a 7, so I'm thinking they call "balanced" a 7. If thats the case you will have to add Ph-(down) to correct the balance from the shell. Or to save some hassle just get a $10 air pump, a few feet of air line, and push it through the clay pellets, or lava rock your using for a medium in your DWC, so it bubbles O2 into the water, w.o. dic%ing the dog with adjusting Ph levels. If you have multiple plants "T" off the air lines to supply air to all the plants, and add in a little H2O2 to the water, and that will give off its extra O2 molecule, to the roots, and assist with keeping algie at bay.
Hope that helps.