ive just managed to crack the base of my fish tank by putting boiling water in it, i forgot to put cold in first. Ooops! :-( is there anything i can use to seal the crack as water is very slowly leaking through it! any water resistant sealant or something. Any help appreciated. :-)
You need to remove all the water quickly as just like a windscreen the pressure on the crack will force the crack to grow and burst completely.
It might be worth putting your tank in the back of your car and taking it to one of these windscreen crack repairers- they may be able to fix it for you?
Phone your local fish shop/aquarium. Usually any sealants are really only for the edges/corners. If you've cracked the glass anywhere else you'll either need to replace it or get a new tank.
How big is the tank?
You may be able to fix it by getting a piece of glass cut to the size of the base and using sealant over the whole base....other wise get a new tank as its going to take a day or two to get it ready to hold water again [you'd need to seal the crack...let that dry, then attatch the new base and let that dry etc].
As Lisa says, the easiest way to do it is to get another base made and just silicon it over the old one. Make sure you use aquarium sealant and not the stuff from B&Q !!!