So I'm coming up on flowering stage here soon and so far I've been using distilled water the entire time. Adding Cal-Mag to it as well. But it's starting to get pricey with 8 plants. Watering approx 1 gallon each plant every 3 days = 80 gallons/month. I do plan on getting a reverse osmosis system for the next grow.
I tested my water ph recently and it is reading a 10! That's with a properly calibrated meter. That seems insanely high. Should I be calling the water company? I don't drink it myself. But that seems like alot of alkaline even for the dogs. Plus it's outrageous here. We pay $100/month for just 2 people.

So my question is...should I use Ph Down to get it back down to 6.5-7 or is that not the right thing to do? Again RO system will be coming next grow. Just trying to get through a couple more months with distilled.
Is there any way you can get a water quality report from your local water municipality? Usually a high pH like that means a lot of sodium and bicarbonates - both which are not good for the soil. The water report will also reveal if you have any chlorine or chloramine in your water - two more things that aren't good for the soil. Also what is the PPM of the water?