Haha...I hate to rain on your sarcastic parade but I thought on it for a
moment. Some gravels are coated in a paint/paint-like coloring and that may
be what they are talking about. I realized this when I was asking about
certain brand names a while back and the lady in the LPS said that some
gravels leech this coating which turns the water and may kill or sicken your
fish.

-Sean

"Ionizer" wrote in message
...
I'm just in the process of setting up two new aquariums, and I happened to
read the "directions" on the back of one of my bags of "Estes'"gravel. I
felt reassured to read that this gravel carried a manufacturer's
guarantee: "If this product is found faulty due to workmanship it will be
replaced."

So far, this gravel is performing within my expectations for gravel, but I
have put my receipt in a safe place just in case I experience a sudden
gravel failure of some sort. Although I had been previously unaware of
the phenomenon of defective gravel, I now feel quite reassured.

The Estes' website goes even further to reassure me:
http://www.estesco.com/beliefs.html

--
Ian.
(Now Playing: Satisfaction Guaranteed - Aquarium Rescue Unit)