Seachem Flouride Black Gravel, is it ok?

Today I bought 30 pounds of seachem flourite black gravel for my planted tank and a little bit of white gravel to go with it. Does it really help with plant growth and is it safe for my fish? I assumed it's safe though I want to make sure.

 

It is safe for fish, of course. A black substrate will make the color of the fish stand out.
I have SeaChem Flourite in three of my panted tanks: two are red and one is black. I am personally disappointed in it's ability to provide plant nutrients and promote growth (compared to Fluval Stratum and Amazonia Aquasoil). Fluorite has sharp edges and can scratch the glass .However, it is heavy and easy to vacuum and to make/hold slopes.
I had a lot of dust with the red Flourite, not much with the black one.

 

How long did it take to wash, I did do some research saying that the substrate is dusty. This is actually a substrate change not a new tank. If I wash it and there's still some dust is it ok to put the fish back?

 

I used a bucket and a garden hose, outside, in my backyard. It took a lot of rinses (10-15) until the water came out clear.
Careful after changing the substrate, you may lose a lot of BB while disturbing suboxic bacteria in the substrate.

 

I am prepared for a mini-cycle. Its a planted tank so the plants will help. What are suboxic bacteria?

 

Those living in deeper substrate where oxygen level is low. They are responsible for converting sulfates to Hydrogen sulfide and organic matter to methane. Both are toxic gases for fish.

 

For this procedure I am removing the fish, will that remove the risk of suboxic bacteria.

 

I would remove the fish and as much of the original water as you can and store it in containers. Remove plants and filter (ideally, I'd run the filter on one of the container to keep BB alive). Remove old substrate, give your tank a good rinse and wipe. Add new (rinsed) substrate, a bit of water, plant your plants and slowly fill your tank with the saved water. Add fish, add Prime, fill up the tank and keep your fingers crossed.

 

Then I will test my water everey day to see if there's a minI cycle.