I put sand in all my tanks, I have pool filter sand in my 55 gal. tank that was about $10 for a 25lb bag. This kind of sand is not as fine and is a courser sand in the beige white color. I like this sand as it is courser then play sand and if you get algae on the top you just rub it between your hands to get it out. This sand took alot of work to clean but in the end it was worth it. I just let the filter run for a few days and rinsed the filter bag every day and put water clear drops. It was really clear the next day. I also have black sand in my 6 gal. and 5 gal. tank. with this sand the poop and any food shows up more on the sand top but it looks nice and is easy to clean because everything settles on the top. I will never go back to gravel. Make sure you turn the filter off while you are filling the tank with sand. Once the sand settles you can turn it back on. The white sand makes the tank so much brighter with black sand the neon fish and red cherry shrimp really show their colors against a black background also real plants show up so nice on the black sand and the black sand is good for plants as it has iron in it.