Are These Safe to Add To My Tank

[jboi]

I was at my local SoCal beach today and found these. One is an empty snail shell with plant growth and the other is a rock with something growing on it.

Before I add them to take I have questions.

1. What are they?
2. Are they safe to add to my tank without destroying everything?

Thanks!

 

[Michael Hoaster]

Impossible to know if they could harm your tank, but it's doubtful. You could give them a quick fresh water bath. They don't look to be in good shape. I would think the temperature difference is huge between the ocean in SoCal and your tank. So it's unlikely they would survive. But you never know till you try…

 

[vlangel]

If you have a spare 10 gallon tank or even an empty 5 gallon salt bucket and an air pump, you could QT them a few weeks and just control nutrients with a few small water changes a week. That way you can observe them first. Maybe even use the cast off water from your tank to help acclimate them to that water chemistry.