Emergency! Sand problem!
Sorry if this is in the wrong forum, anyways, I am currently having a huge problem! So a week ago I purchased a new 37gallon aquarium kit as well as two bags of CaribSea black sand (Tahitian Moon Reef.) As I was cleaning the sand, I noticed a strange film on the surface of the water in my bucket. It resembled and smelt like oil but I figured it would go away. So I cleaned the sand (which also dyed my hands and the bucket greyish-black) and then began to put it in the aquarium. Keep in mind, I thoroughly cleaned the sand, removing all of the strange substance, but the odour remained. The sand dyed the water grey so I called the shop I bought it from and they said this was normal, I just needed to turn the filter on for a while. The filter has been running for 5 days and it is still somewhat discoloured. I don't mind the discolouration, but there is a strong smell similar to that of oil.
So my question is, is this sand toxic to my fish? What is wrong with it? And how do I fix the problem?
Side note: My betta has been living in the tank for four or so days and it seems to be doing fine, but he is pretty resilient. I really need to move my axolots into this tank but I am worried it will kill them!! Please help!