Tanks are ridiculously expensive, so i figured it would be way more efficient just to make one, does anyone know how to do it somewhat easily? How much would the supplies cost?

I have a 100-gal pond made with a prefab liner. I have a 450 gph pump running water through a "makeshit" waterfall made out of slate stacked on top of each other with two landings. How do I make a "real" waterfall so the water flows evenly along the width of the slate instead of just dribbling...

I'm new to the aquarium scene. I've done alot of searching and looking but need help.. I want to stock my tank with dwarf gourami rainbow fish and anything else anyone would suggest. is this a good idea? I have all my equipment but a heater, what size should i be looking for? I'm thinking about...