White balls

[dherrington1]

I've got ~11 of the brackish snails from Mufasta with 24 shrimp in a 6.5 gallon tank. I'm now seeing small white balls, individual, sitting on top of the substrate, which is black. They look like extremely small round white pebbles, and there are now approximately 10 that I can see scattered all over the tank. They're not attached to anything like nerite eggs would be, but I'd swear they are snail eggs. Can anyone confirm that's what they are or let me know what they truly are? This is the 3rd tank, progressively getting larger since last year, but this is the first time I've seen these show up. Interestingly I pulled one out and let it sit for ~2 hours and it has turned black.

[Mustafa]

If it feels like sand, i.e. hard to the touch, then it's probably just some white sand particles mixed in with the substrate. Happens. Not sure why they would turn black outside the water, though.