How to clean used tank

[benj420]

I just scored a 50 gallon glass tank, stand, JBJ lights, glass lid, unknown powerhead (looks like the square Rio's), and Penguin filter for .......... $75. WOOHOO!!
The tank has some dried, crusty growth on the inside sides. I don't know what you call this stuff, but I have seen it on every SW tank. How do I clean it off? Also, I know it was a SW tank, but don't know much more. Should I sanitize it somehow?

 

[gregzbobo]

Either vinegar or muriatic acid from a pool dealer. That will take the hardwater deposits off. Won't hurt the tank at all, and it definitely works. Vinegar just takes longer. After doing the acid wash, use plain tap water to rinse it out. When I used to clean 10 gallon tanks, I would wash them with tap water and a few tablespoons of table salt. You don't want to use soap of any kind.

 

[slick]

They do sell special tank cleaner. I have never used it before but you might try it.