i know stupid question.my dad had a leak in his tank and siliconed it up,it leaks no more.ok so anyways he siliconed it right but he left all the decorations and gravel in the tank when he did this.ok so he fills it up and now there's this film slimy stuff on the top of the water.so he took a cup to get it out,he did not get it all out and is going to turn the filter on to get the rest out.tell me what you think?are the fish gonna die?i think so.