no worries william, i hv done some reading/research a couple of months back on the proper type of sealant to use for the construction of a glass aquarium. apparently, there is no conclusive answer.
u can read abt it here.
as far as DC silicon sealants r concerned, seems like it is quite debatable btw DC788 (Penetrator), DC791 & DC795.
hope i did not dampen ur spirits in anyway, since ur tank has already been delivered. maybe DC791 is really the correct silicone sealant to go for after all.