Ok I have some what mixed reviews of sand. To me it all depends on the type and how much you use. If you you play sand, use very little because it pack down good, also traps bad gasses in it. it also gets in filters quickly and then they are noisy! you can beat these problem a few way: first use less sand. Second MTS. third buy fish that dig in the sand. And finally make sure the suction from your filter is 4+ inches from the sand. also play sand looks good till its dirty.
Now for they type I like the most, its not so much sand but very similar is agronite sand. this stuff is kind of pricey at most places. but the good stuff usually is. Agronite is usually kept in reef tanks, but can be kept in fresh tanks also , but you have to watch your ph. Agronite has many other good qualities too, it light enough for fish to move, but heavy enough not to get sucked up by the filter. It also helps to buffer the ph in the water.
It also gives a reef look to a fresh water tank.
I currently have two different tanks, one with each type. If I had to do it over again I would only use agronite!
