IMO, I don't have any disadvantages with sand. If you use something like pool filter sand, it is very easy to clean. Just fill a bucket 1/3 full of sand, stick in a garden hose and swish the sand around with your hand for about 15 minutes with the water continuously running in the bucket. This will pull up the dust and debris. I did it this way and haven't had any cloudiness.
Toss in some
MTS and you don't have to worry about stirring the sand. I still do it about twice a month, but that's just because I have a mixed black and pool filter sand look in the tank and I'm still mixing the two colors together. But, this isn't really a big deal to do.
Cleaning it seems alot easier than with gravel. When using gravel, fish waste sifts its way between the gravel. With sand, it just sits ontop of it. So all you have to do is wave the gravel vac above the sand to kick up the waste, and suck it out. With a heavier sand (like pfs), you can push the gravel vac into the sand about 1/2 inch, then tilt it to the side and shake the sand out. Only minimal amounts of sand will be sucked up. I probably average about 1 tablespoon when doing the weekly water changes. But that is a combination of the 10, 29, and 150
gal tank.
We used to ONLY have gravel tanks. Then we sanded the 55
gal beacuse of our eels and loved the look of it. At that time we used sand from the
lfs. It was light and we had alot of cloudiness and clumping. When we did the 29
gal tank, we used pool filter sand. No cloudiness or clumping. So when the 150
gal tank arrived, the cost of sand vs gravel was obvious. It was SO much cheaper to sand the tank than use gravel. Then I converted the 10
gal over to sand a couple months ago. The 5
gal is going to be converted when we move, and when I setup the new 55
gal tank, it will be sand.
It's basically just personal preference. I like the ease of vacs with the sand over gravel. Depending on which color of gravel you use, the sand looks more natural. Plus, my fish LOVE to play in it. They make little pits in it and sleep in them.
Also, I haven't had any issues with sand harming the impeller of the filter. It is a good idea to use something to cover the intake tube of the fitler for the first couple days. If it is a lighter sand, you may want to keep the cover on. But if it is heavier sand, you don't really need it. The sand should stay put.
This is
JMO.
YMMV depending on the type of sand that you use.