[OVT]

Tahitian Black Moon sand has been discontinued (after some controversy over polluted batches).

IMO, Dutch style looks better with black, island / driftwood dominated scapes with white. So, you might decide on the tank "style" before finalizing your substrate choice.

Beside upkeep of white, some fish species have light phobia and should be avoided with light substrate. Cardinals being the prime example.

I don't belive the substrate color has much, if anything, to do with algae blooms. I would look for other causes and remedies.

 

[OVT]

Really? Because I bought some in May 2018 that I had an extra two bags left over that I was planning on using. Still unopened since then. Think its okay to use?

The kind of sand I used in the past that I had terrible algae problems with was Caribsea Sunset gold. I really liked the look of it though especially compared to black sand.

There are a couple of threads on TPT and more on the web where fish deaths were blamed on Tahitian sand. I bought mine some years ago with no issues. I would call CaribSea to check if they have a way to track batches. I can count 4 colors of sand and 2 colors of < 1 mm gravel that I have used from CaribSea with no drama. On the other hand, I had no end of problems for a year in a single tank with new AS. I used Fluval Stratum one time that literally turned to mud in 3 months in 8.4 pH water. So, personal experiences all over the place.

Buying substrate, especially sand, on line gets really expensive because of shipping weight. I went temporarily insane and did buy CaribSea gravel for my latest 140g.

I would check LFS in your area to see what they have or can order.