Not sure about this, but I feel you should have more surface agitation, I have a long air stone in my 55 gallon, plus a sponge filter. I can tell by your short video that your plants are swaying back and forth so that is good which means your filter is moving the water. Its imporant that all the water as much as possible moves in and out of your filter that way you don't end up with to much in the way of dead spots.