i was watching some youtube videos on aquariums and I came across the concept of underwater waterfall. I attached some links below in case you are nto familiar. From what I have researched there are two ways to achieve this. first way is to use air stones which is a very simple concept but i don't want any bubbles in my aquarium. The second way is to use a water pump but I cannot find any information on what kind of pump to use. From my experience you cant just use any aquarium pumps as they get clogged and don't work when you introduce any sand in there. The second you tube video link is exactly what I am looking for. They seem to be using the water pump method but I cant figure out what kind of pump it is. If any one can help me out in any way, I would really appreciate it. I will also post my build as I go along.
http://www.youtube.com/watch?v=kDVD1Q3W53A
http://www.youtube.com/watch?v=OeBbGDXp76s
http://www.youtube.com/watch?v=kDVD1Q3W53A
http://www.youtube.com/watch?v=OeBbGDXp76s