<https://forum.aquariumcoop.com/topic/12409-why-are-ugfs-not-very-popular/#comment-97746>
<http://schema.org/text>
"The linked article eventually got around to saying that plants prefer a finer nutrient rich substrate. \n \n\n\n\tEnvironmental conditions in each of my tanks vary enough to make drawing one conclusion impossible. Plants in the UGF/gravel tanks are doing better than the plants in the gravel only tank. Pea gravel that has been rinsed to remove only the dust seems to retain more detritus, and I have occasionally found fine gravel stuck in the screen protecting the powerhead.  for that reason alone, sand is out of the question for me. \n \n\n\n\t \n \n\n\n"
<https://forum.aquariumcoop.com/topic/12409-why-are-ugfs-not-very-popular/>