I wonder if that stuff is black diamond blasting sand? If so that stuff seems to have mixed opinions online if it is toxic or not, I lost 2 of my three lined corys which I suspect was due to my gravel as the remaining 5 didnt look great either, switched to playsand and they bounced back, all in good health and love sifting/burying their faces playsand as it has smooth granules.
Not sure if it was due to the gravel or maybe waste getting stuck between the gravel and rotting into nastyness.
None of my mid water fish died during this time but I did lose a shrimp or too (now they are everywhere).
Not sure if this anecdote helps but it hopefully shows substrate alone can affect bottom dwellers while midwater fish do fine.
*edit: sorry was Tahitian Moon Sand that has mixed opinions regarding toxic heavy metals, forgot why I didnt go for blasting sand, think blasting sand has sharp granules but isnt toxic.
If your shrimp were affected, it isn't the same I think. I have 5 Vampire shrimp that live constantly in the ground, and I have keep some neocaridinas and amano shrimps without problem too.
Here is a review from another user on the sand:
"i was a bit concerned buying this as there were no reviews on here yet, but decided to give it a go, as it was such a good price compared to others id seen, i was worried about cloudiness ect, but this sand is great, i rinsed it thoroughly {packaging said to rinse until water runs clear, it was clear straight away, though i did continue rinsing just incase) i then soaked it in water conditioner before adding it to the tank, my tank was already full of water and this fell beautifully straight to the bottom of the tank, no clouding or anything it just settled beautifully, there were a few air pockets which made a few bits of sand form little balls which floated about, but you just pop them and they fall to the bottom too, it has a lovely deep black colour, although when i put the bright light on in the tank it makes it look brown, but i don't often use this light, so that's not a problem, it also went a lot further than i thought it would and i have plenty left for my large tank when i get it, i will be aquascaping the large tank so although its massive i will only use it at the front, as the back will be soil and plants.
my corydoras seem absolutely love it, its nice and soft for them to big around in 🙂🙂 i'm so happy i bought this and i highly recommend it
🙂🙂 also was very quick delivery and great price"
