I did the background waited about 16 hours or so and put silicone on and substrate, then waited overnight. Next day set the tank up and brushed off substrate that was loose, it's been sitting for about a little over a day and the foam has started to separate from the glass ( there are spaces where a frog could climb behind and get stuck) so my question is can I go back in the way it is and fill in gaps with more foam or how do I go about getting the foam off to completely restart? Please help!