I recently purchased a couple of 15lb bags of florida crushed coral substrate to replace the aragonite sand substrate in my FOWLR tank. Although the package says "pre-washed - only minimal rinsing required" I did not find this to be the case. :down: I spent over an hour rinsing each of the two 15lb bags, and it still clouded the water. I have been impressed, however, with how it really doesn't compact. :up: I originally wanted to purchase super-reef, but was unable to find it in stores, but have to say, I think I actualy prefer this now. I especially like the little seashells mixed in with the coral bits. The price was better, too.

I purchased this stuff also, and its horrid IMHO.

LIke you said, it says prewashed, and I spent over 2 hours rinsng and soaking it, and the water still came out like milk. Not cloudy.... it was pure white. Eventually it somewhat cleared up, and I started using it in a ten gallon when I first started with sw....although I liked it then, it did cause a lot of troubles with my tank. I prefer sand over crushed coral anyday. While I don't prefer it as a main substrate, it's an awesome buffering material. Cheap, around fifteen dollars for a big bag, and great for someone dealing with multiple systems including quarantine tanks. I usually have a small bag or two hidden in my filter when working with quarantining fish or inverts.

I think I now know why it comes so dirty. After a few months of use, I have been noticing more and more sand particles because the substrate is eroding quickly.