so today is the last day that i ahve to let my tank set for but a friend who has helped me do the tank said that i should set the tank up and put the filter in and use rock salts for 3 days to kill the stuff thats in the silicone but the silicone says that it can be used on fish tanks and will the rock salts kill the bactria in the filter good or bad idea bout the rock salts??? thanks heaps jed

I wouldn't use the salt. No salt won't knock your filter out.
I would fill the tank outdoors. make sure you have it on a good flat surface or the bottom will break. fill it make sure you have no leaks. wash it with clean water then set it up. if the silicon you used was safe for fish you should be fine.

how have yr fish coped in the smaller tank? my offer still stands, if u need my help id happily except plane tickets down under in exchange for it!!!

x2 on the no salt part...once the silicone is dry there aren't any harsh chemicals released so you will be fine without the use of salt. Basically the chemicals released during the drying process are what is toxic but after about 24 or 48 hours (depending what kind of silicone you got) of drying it won't be toxic anymore.

But yeah...test fill outside or somewhere that can get wet and let it sit for about 24 hours checking for leaks...after that if there are no leaks I would say you're good to go...same thing I did with my 90 gallon.