Flourite is a great substrate. I just wanted to post because it's widely known how cloudy Flourite makes the water when you first fill it up.
Well I just started a brand new 55 gallon tank.....and had absolutely NO CLOUDING!!! First I added LOTS of mulm from other tanks. Then added 1 large handful of pre-boiled peat to the bottom of the tank. Thirdly I started rinsing the gravel. I added 5 bags after I rinsed in the following way. I used a paint strainer (the firm kind that lays in the top of a 5 gallon bucket) and filled it halfway with flourite. Then poured water from the garden hose through it until the bucket was filled with cloudy water. I did this until 2 1/2 bags were rinsed and I had the rinsed flourite filling up another 5 gallon bucket. I then poured water into this bucket (already full of flourite) and dumped out as much water as I could. I then laid this on the bottom of the tank. This layer still had plenty of "dust" particles (which are high in nutrients).
For the top half of the gravel bed, I Did the same routine with the paint strainer, but when I had rinsed all the flourite, I then poured about 1/4 bucket of the flourite at a time back into the (cleaned out) rinsing bucket, and swished water around in it and dumped it out twice. After all this was done. I laid it on top of the other gravel. I then laid a small (almost flat ) saucer on the gravel and SLOWLY started to fill it up. If you fill slowly enough you will have ZERO CLOUDING!! My tank has been clear since day one! Of course it does cloud a bit when I disturb the gravel, but quickly settles back down.