crushed oyster shells

[kjd277]

Can you use oster shells from your local beach and crush them up to use in an african tank. Do you have to clean them or use them as is. If you have to clean them how do you do this, any special way. Also what is the best way to use it. Mix in with gravel or put directly into the filter with something like a nylon sock. Trying to help buffer the ph. Figured i'd take the cheap route. Thank You

[blitzen25bm]

if you wanted to try it you can get crushed oyster shell at a feed shop for like 15 cents a pound. im pretty sure theres no additives since its so cheap so a good rinse and they should be ready.