Is this sand any good?

Just my 2-cents but I would go with all new sand, In fact that is what I did do when going from a 75-gallon tank to my 150 I just cant see taking the chance. But that is me.

 

hydrogen sulfate in the DSB

HI,
MAny times we are very concerned about hydrogen sulfate, it is metabolised by bacteria, some worms and can be made fairly harmless in the dsb when combined with IRON, The worst thing to do is stir it up if its a DSB.
Here's a well written article that is more info than needed but shows the many pathways hydrogen sulfate in the DSB is bound and made harmless.
Doug
The black material you see in many dsb is iron suflate or bound hydrogen sulfate. so black in the plume may be normal.

Hydrogen Sulfide and the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com

 

I have a little monitor I wear at work just to avoid this stuff

 

Last year, a couple people on the maintenance staff of a very famous cruise line died when they forgot to off-gass the H2S prior to them doing the work.