1. I've never worked with a Diamondbrite pool, so I can't answer with certainty.

2. Chemical imbalances do not cause you to have sand in the bottom of the pool. Sustained low pH can result in finish damage, and sand-like particles. Get some of the particles, and look at them closely to see what they are.

3. Unless your Diamondbrite finish already has "green/blue specks" in it, such specks are not from the Diamondbrite.

4. Most Portland cement based pool finishes (like Diamondbrite) do not HAVE to be replaced till they become so rough they retain algae OR so thin the gunite shows through. Before that, you MAY replace them, but it's just a matter of preference.

5. "green/blue specks" CAN be from copper flakes, if you have anything copper in your pool -- like a heater.

6. In any case, we can't really help you with your chemistry, till you get a K2006 (see Amazon link in my signature) -- test strip results, even from a dealer, simply are NOT accurate enough.

7. Meanwhile, if you use borax and muriatic acid (see link in my sig) to keep your pH between 7.0 and 7.8, any ADDITIONAL damage should be minimal. Get a cheap local OTO/phenol red (yellow/red) drops kit to test with, till the K2006 arrives.