I just bought a bag of that myself, and I would definitely advise you to rinse it beforehand. I used a pasta strainer that I didn't mind getting dirty, with the holes not too big, and rinsed it in batches with the garden hose, until the water ran clear.
Rinsing Flourite before putting into the tank is a bad idea for two reasons:
1. The stuff comes wet. Anything it touches will have Flourite mud all over it. Like your clothes. Or your carpet. The only place you want to open a bag of Flourite is INSIDE YOUR AQUARIUM.
2. Rinsing is hard work! I'm lazy!
Here's what I did on my new 75g.
1. Put unopened bag of Flourite in aquarium. Cut open. Pour out of bag. Discard bag. Repeat.
2. Partially fill tank with Python. This thing is a godsend! I would not have a big tank without one!
3. Stir up the Flourite to muddy water as much as possible.
4. Drain tank with Python. Have the water empty out into your lawn. The dust is powdered Flourite produced by friction from shipping. You paid for it - don't waste it.
5. Repeat if and as necessary (i.e. until you can't cloud up the water any more).
Used a lot of water but sure saved my time and back!
You have to rinse flourite a LOT--it doesn't come wet--it ought to be dry. I wouldn't rinse it in the tank, since it leaves "sludge" behind. I'd do it outside or over a bucket with a strainer. I used a python, a bucket, and a strainer. It takes a really long time to get it clean.
The procedure I described is probably best suited for big tanks. Straining a bag or two should be easy enough. I was using eight bags.
My Flourite definitely arrived moist. In fact, after I opened a bag in the aquarium and let it dry out, it changed to a lighter color.
If you can't get the "sludge" to suspend in water long enough to pump it out no matter how much you stir the Flourite up, it's not going to be a problem in terms of clouding up your water.
I'm just proposing an alternate method that worked well for me.
It didn't take me a really long time to get it clean, and my water is clear.
I filled my 75-gal planted with 1.5" of flourite and then put an equal amount of substrate right on top. I put a plate on the substrate, a tea pitcher on that, put a garden hose in the pitcher, and just set the hose on dribble. I stopped the hose after about 5" to plant my plants, and then reset the hose on dribble again. A couple of hours later I had a full tank, and a day after that crystal clear water. I didn't even rinse the substrate either...
From what I understand, you need to rinse florite. If not, everytime you do a water change which should be often, then you will have a cloudy tank from the florite. After several water changes then you will not have this problem anymore.
it's a great substrate base but it's messy..I did mine in large buckets(5 gallon) and drained it in the front lawn..the lawn loves me now , tho there is this one section that is greener than the rest of the lawn :joke:
marine mom is correct even after rinsing you may see some silt it will get trapped in the filter and will settle out of the tank.