This can be sound stupid , but i got this stupid idea of putting ADA bactor 100 additive underneath the tank bottom and build deepsand bed on top of it , ADA describe bactor 100 like this '
" Bacter 100 is a substrate additive, containing more than 100 kinds of substrate bacteria in a dormant state. By sprinkling on the base substrate, it can make an ideal substrate environment. By applying on top of blue green algae, it suppresses the growth of it."
will it help to grow helpful bacterias on sand bed , will these bacteria survive on saltwater ,, give me your ideas about my stupid methode