See I havent tested it for silicates yet, the high nitrate content was enough for me to stop using it, im sure my Petco has that in their water too. They used to charge on their water, I should of known once they made it free that something was up. Oh well, the tap water in my area is the best ive ever seen and tasted and ive been all over the world, so I have an API tap water filter on the way, im gonna see how good that works, ive heard excellent reviews. Its gotta be better than what I have been using.