Most plants take most of their nutrients from the water column, through their leaves. There are some exceptions(like Amazon Swords), that are root feeders.
Are you feeding anything, and if so, what? And what is your lighing situation?
Flourite is a great substrate, but very difficult to add to an existing aquarium because it clouds the water. I'm not talking about anything like you can imagine. I'm talking......like coffee.
Get yourself a 5 gal. paint strainer(Home Depot/$2), dump about 1/3 - 1/2 bag of Flourite into the strainer over a 5 gal. bucket and rinse it until it runs clear. Remove the 'clean' Flourite and repeat the process until it's all washed.
Before you add it to your tank, I would strongly consider removing the fish to a bucket and saving the water that's presently in the tank to buckets. Save as much as possible. Then add the flourite back into the tank. You can mix it or lay it on top.....whatever your preference.
Lay an empty bowl on top of the substrate and fill it til it overflows with your saved tank water, and keep filling the tank back up that way to create as little disturbance to the Flourite as possible. You will still see some clouding, but much, much less than if you don't wash it well beforehand.
You will love this product, but it's just a pain in the butt to add to an existing tank.
Len
