I have some crypts and a sword plant and they wont stay rooted I use everything that aquarium coop says to use like seachem flourish and easy green and they work. I looked at the bottom of the tank and a lot of my roots go to the very bottom of the substrate. The plants dont come out of the gravel and float to the top they just come out a little and then you can see the roots. I bury the roots and they come back up. should I add more substrate? Thanks!