Well the only reason I'm forced to do this is I learned that this is made of a bio plastic, and 100% silicone sealant will only work for a half a year or so, and teflon tape could take many many attempts to get it right, so I figured Id drop a liner in it, then no sealing no nothing just simple liner, then once all together I'll put in sand and 3 columbian sharks .
P:S could there dorsal spines rip the liner even if 40 mls thick