FREE: GREAT lot of LARGE sea shells, sea biscuits (sand dollar) coral & urchins ~ MUST SEE!

It would probably be best to check with an aquarium person at the pet store, however, the largest clam shell was in our tank for a long time. My concern would be with conch (in the back) as my mom shellacked or coated it with a shiny something-or-other. The other two conchs would probably be ok. As far as the urchins, the coral, and the sand dollar biscuit, I would soak them really really well, as they may have been bleached (or colored).....the big clam was bleached too, but we just soaked it for a week or two (changing the water every couple of days) and once it was in the tank, we had no problems. Hope this helps!