ident Algae how to treat?

[Myka]

You can go to most drinking water supply stores and have your water tested, but it's not cheap!!! I think they start around $70. You would be best off adding more stages to your RO/DI like adding a second RO membrane, and possibly a second DI. Use your TDS meter to check the water that comes out of your RO before it goes into the DI. If you have more than 20 ppm going into the DI you're burning that DI out, and should definately add a second RO membrane. The water you add to your tank should be 0 ppm tds, or at the very most 2 ppm. How many GPD is your unit? Some of the faster ones are less efficient.