May be a dumb question but I have a kanger aerotank v2 long story short Pyrex glass and a good fall onto concrete equal a crack. No big deal though I have a stainless steel replacement. I tried to get the glass off but it wot budge and I have a good grip. I my fingers around the mouth peice and too of glass but the bottom won't budge. The top will come off but any tricks for switching tanks. Thanks