I don't know why the bulb plant is long and stringy. Could be the lights...flourescents too heavy in the red spectrum can cause plants to get a little lanky.

The bananas should only be planted 1/4 - 1/3 the way into the substrate. If they can't anchor in your pebbly substrate, then maybe a pot for them? you could bury the pot a bit so it's not sticking up so high, and put the flourite or other substrate in the pot.

Dr. Barb...I love your little drummer happy guy...where's everyone getting the little icons from? I see Virg and Sarah have them, also.