gravel looks cleaner longer. The fish poo and leftover food settles through the cracks between the gravel and collects there. With sand these cracks don't exist so the poo and food just settles on top. I think this is a good thing because sand reminds you that you need to do a waterchange. Cleaning both substrates is easy. With gravel you just stick the syphon into the gravel and suck out all the crap. With sand you hover about a half an inch above the sand and swirl the vaccum. This will suck up a bit of sand but not much. The one point on which gravel is better than sand is with anaerobic bacteria. Anaerobic means that it doesn't use oxygen. This bacteria causes gases to build up in the sand because no oxygen can reach more than an inch or so into the sand. These bacteria can be prevented by stiring the sand. having a 1" sand bed. Having fish the stir the sand, like khuli loaches corydoras or malaysian trumpet snails. Sand is cheaper than gravel but it's harder to clean. Clean gravel with a sive and a water hose. Clean sand with a bucket and a water hose. put a 1-2" layer of sand in the bottom of the bucket and fill the bucket with water. Count to 5 and dump out the water leaving the sand in the bottom of the bucket. Do this until the water clears completely in 10-20 seconds. I got my water to clear in 7 seconds but I rinsed very very very well. Sand CAN DESTROY hob filters. If sand gets to your impeller it can ruin it. This can be averted by placing the intake several inches above the sand bed. You can also add a prefilter sponge onto the intake of the filter. But if you don't stir up the sand really aggressively there probably won't be a problem. Refilling and stirring are really the only times you have to worry and you can just shut off your filter during maintenance. You should also look into what fish you have. Something like a shelldwelling cichlid would demand a prefilter on an impeller driven hang on the back type of filter because they vigourously stir sand causeing it to regularly get sucked into the filter. I hope this has helped. Any questions that I didn't answer?
