Hi I have found 3 cuttleshell on the beach - can I put it in my aquarium (water too soft I have I apple snail - new)? Also found some shells and these clusteres (some white - some beige) as hard as a stone - is it faceas of shells(similar thing as a coral)? Can I put it in the aquarium - is it safe? And again - how long shall I boil these things? It will not raise the ph too much will it? And the last question - is it ok for the fish in the tank.... I have harlequins, botias macr., silver dollar, punteus titt. Thanks again to everybody for help.... Lucc