The 3M color quartz testing is looking very good so far. I purchased white, it is an off white and no where near as bright white as the carib sea white sand. Still an attractive substrate and it looks more like "normal sand" in that it is larger than carib sea.
Test tank: 20 gallon long, no heater, 1 large sponge filter, 1 penguin 170 filter, no lights, a few residual snails are its only inhabitants.
I poured about 20 pounds of the substrate into my test tank without rinsing. (I had read on one of the fish message boards that the color quartz doesn't need rinsed, so I am testing that as well. I have a diatom filter to clear the tank with if it doesn't clear on its own.) The water was very cloudy for about 21 hours at 24 hours it was pretty clear. 36 hours and the cloudiness is barely noticeable.
I used the water python on it to see if it sucked up as easy as the carib sea sand does. It does not. It vacuumed very nicely, I could stick the gravel vac tube clear to the glass bottom of the tank and pull it back slowly without sucking up the color quartz.
Since I recently removed the aquarium gravel from this tank there was a lot of the "brown fluffy stuff" that had settled on top of the sand. I did have to use my faithful pen plax battery operated vacuum to clean that up.
I will post more on the test later. I am waiting for a new filter to arrive for this tank. I am going to try the Aquarium Pharmaceuticals RENA Filstar XP 1 Canister Filter so I can compare it to the Fluval 204 canister filter that I really like.