Good old fashioned playground sand, in a 1 to 3 inch layer. It's a lot more work to set up, but my fish love to dig in it, my plants root well in it, and I've never had a problem with cleaning it. Plus I can always go wash more out as I slowly remove it in tank cleaning. Keeps it turned over and fresh, to the tune of about 50lb bag every six months.
I don't know what the problems with sand are... I've only had good experience. It's just as easy (if not easier) to vaccum the detritus off the top of the sand as it is to dig it out of the gravel. The problem there is that with gravel you can't tell it needs to be done like with sand
Since the first couple weeks, the only way the sand gets stirred up in a noticeable way is if I uproot a sword plant (lol... they have a LOT of roots). No problems with the filter, even after I didn't wash the sand properly before adding it originally. Have to wash a bit of sand out of the sink after water changes... but that's it.
I use swimming pool filter sand and fluorite mixed.
I went with the filter sand because it's cleaner than play sand or construction grade sand. It was only $7.50 for a 50 lb bag. A lot cheaper than the stuff going for $50 a bag! Wow!!
I think I will keep the Gravel in my 55 untill I get the 75G then I will move the fish to it and use the 55Gal as a marine tank, then I may use sand, Any suggestions to the marine tank?