What is the build up/gunky looking stuff on the side of the tank I see in most pictures? Does it come off? Is it like an algae?
Click on the link to see what I mean:
http://www.fnzas.org.nz/fishroom/chimer ... t4982.html
Sorry for my ignorence, but I would love to put a marine tank in my living room wall, but that build up dosent appeal too me.
Thanks for your help in advance