Hey, first off I am new to the board. I am down in the gulf of mexico on vacation and I am seeing alot of great rock on the beach. At home I have a 100 gallon tank that I want to build up with some nice base rock before I invest in the nice top rocks. So I wanna take some of this rock home but I dont know if its going to be safe in my take. What it looks like is pretty much a bunch of shells suspended in rock. Its a very light color. I have about 30 pounds I wanna take back home with me to add into my take. Will this be safe in my tank?? Any help would be great