I just bought all the parts. I am going to put them in neoprene foam circles. When I put the stems in the foam, how much of the stem goes below the water or how do I keep it above the water???? Thanks
For a bubbler, you would want the stem ends just above the water, in that zone where the bubbles form the mist layer. You want the end to be in the constant mist, and your roots will grow down for more water while the roots above will get the needed air.