i am in England mate, so i got mine from a shop called Homebase, it was only 3.99 for a 2.5kg tub, and after what i used i think i will have enough for three coats in this tub comfortably.
i think it is called evo-??? something or other i think it is the equivilant to that stuff you guys have in the states called quikrite waterproof cement? but i am not certain.
i can't wait to get the second coat on tonite now and get it back in the tank, i am going to put it back in the tank, cover the tank and let the cement dry slowly i think, then stick it in the tank with a Shed load of sealant and then apply the 3rd final touch up layer (which i will mix a bit of sand into for texture) while it is in the tank.
sounds almost too easy..something is bound to go wrong