Black sand

[HuduVudu]

Stay away from the black sand it isn't iron that it has it is Vanadium. You will only see that on an ICP test. You really don't want that in your tank, and it is really hard to dilute out. This test that I am posting is AFTER I removed it and had done several water changes to try to dilute it out.

P.S. Basalt isn't good choice either.

 

[CC_N]

How about Seachem gray coast ? A lot of people use it