Invertebrate die off after change of substrate

[Ginkgo]

Hello, I recently re-scaped one of my aquariums using a new substrate, I wanted black sand specifically, but couldn't find any locally and unipac sand looked grey to me. On further searching I found what seemed to be true black sand listed on ebay - this stuff The day after the re-scape my neocaridina shrimp and ramshorn snails died, the fish however are fine. All the parameters are ok, unfortunately I don't have a test for metals.

I've messaged the seller to try and figure out where this "sand" is obtained and what it consists of, but as of yet I have received no response. I'm hoping that someone on here could help me figure out what this stuff actually is, and what in it could have caused my invertebrates to die off. My only guess is that somewhere along the line the "sand" may have been exposed to copper, or other harmful chemicals in the production process. I am to blame for this, I should not have used an unknown substance in my aquarium. I will not be making this mistake again.

If anyone could clue me in on what this stuff is, and what may have killed my invertebrates, I would be grateful.

 

[Hufsa]

Could you post a close-up photo of the grains of the sand?

 

[Hufsa]

I didn't go through every review of the item but I found a couple who appear to have similar experiences to you. I suspect your sand is not of natural origin, metal slag, industrial waste product or something made only for sandblasting. Olivine sand or aluminiumsilicate maybe.
If I were you I would remove all the black sand from the tank, leaving behind a bare bottom if necessary. Your fish may still be in danger, just less sensitive than shrimp and snails.

 

[Maf 2500]

Sounds like some kind of coal slag such as that which is sold in the USA as "Black Diamond Blasting Sand". Often used successfully by all accounts.

I actually have a couple of bags of this or similar stuff that I bought off ebay a year or two back. Mine came in plain white plastic bags. When I examined it up close I found some tiny thread-like or icicle-like structures that gave an indication of its industrial heritage. I have been reluctant to use it as of yet and I am getting less and less likely to as time progresses.

Edit: I see @Hufsa has similar thoughts, will look at the links posted above

 

[Ginkgo]

When I examined it up close I found some tiny thread-like or icicle-like structures that gave an indication of its industrial heritage. I have been reluctant to use it as of yet and I am getting less and less likely to as time progresses.

That's exactly what I have, the "icicle-like" structures imbedded themselves into my skin while I was washing the sand, that should have been the point where I stopped. I can't imagine it would be pleasant for bottom dwelling fish either. I'm going to ditch the sand altogether and restart.

Thanks for your input @Hufsa & @Maf 2500

 

[Maf 2500]

I went back through my ebay history and the "sand" I bought was from the same seller as @Ginkgo . I enclose a close up picture I took of some of the grains, if you could call them that. I have attatched a picture and you can see why I have never used this product, and now never will. I wonder if it is contaminated with copper as this would affect invertebrates first and would be more toxic in soft low Ph water such as the discus keeper mentioned in the reviews above. So sad for your loss and that of others. Fortunately I am only out for the cost of two bags of sand.

 

[Ginkgo]

Appreciate the help and effort @Maf 2500 . It's the old adage of you get what you pay for. At least you were wise enough not to use it.

It was an unfortunate lesson at the expense of my shrimp & snails, the colony of which was several years old. Fortunately I divided the colony amongst a few other tanks not long ago, so they live on.

 

[PARAGUAY]

Pets at Home sell a black gravel but quite fine like sand . With root tablets l would think it would be a good growing substrate plus you know it's safe

 

[MirandaB]

I bought some of that stuff a couple of years ago,it went straight in the bin after I stuck my hand in the bag and ended up cutting myself in several places.
It's like a crushed glass which made me also think it's some sort of industrial byproduct and it's not certainly not fit for purpose.