Made the switch to sand...
A couple of weeks ago the fluorite and gravel substrate that has been lining the 90g tall tank in my office for the past 15 years was replaced with sand. Having no experience with sand substrate before, I am really pleased with the results and wanted to share a couple of things from the experience. This tank has 3 Magnum 350 canisters underneath, and the media from all 3 was saved and re-used to avoid cycling all over again.
What sand to use?
There is much information available to read regarding what type of sand to use, with proponents and detractors for each choice. I was leaning toward aquarium specific sand from the LFS. However, in the end I went with pool filter sand from the local home supply warehouse. ~$18 for 150lbs. It wasn't as white as what I thought I wanted, but ended up looking much lighter in the tank.
Cleaning the sand.
Everything I read on the subject recommended cleaning the sand by rinsing repeatedly until the rinse water ran clear. There are many experiences to be found of those who did not clean their sand (both from the LFS and the home center) and ended up with cloudy tanks that did not clear up for days or a couple of weeks, after repeated water changes.
Rinsing sand sounds like a lot of work. I performed a test of the soda bottle method of installing sand in a 5 gallon bucket of water using fresh out of the bag, un-rinsed pool filter sand. After pouring in a liter of sand and removing the bottle full of dirty water, the sand was stirred up by hand. 5 seconds later all of the stirred up material had settled out and clear water remained above. That's it, no rinsing for me. And no cloudy tank after installing 125lbs and filling it up.
Other nice things about sand:
Putting in plants is easy-peasy compared to gravel. I have about 3" of sand and recommend at least that amount for easy and secure planting. With the same lighting (1 Satellite + Pro 48") and fertilizer regimen, the plants are showing new growth and looking good. I also planted some new dwarf hair grass which is putting out new growth. A previous attempt with dwarf hair grass in the gravel/flourite substrate failed when it never showed any new growth and died in a few weeks. There was originally about 2" of gravel on top of 2" of fluorite, so the first hair grass effort would have had its roots in gravel mostly.
The bottom feeders seem to enjoy it. There are a 9" pleco and a 6" algae eater, and both have burrowed out residences in the sand under a java root where they spend a good deal of time. Before they spent most of their time in hollows in the root. Also, they are both out more now and spend time less time on the glass and more time moving about the bottom scrounging for food.
So far it's easy to clean. I use a straight siphon (no faucet hook-up) and the vac picks up debris while leaving the sand behind. Vacuuming and water changes take less time because I just move the vac over the surface of the sand instead of sticking it into the surface of the gravel to get debris that has worked its way down into the substrate. This results in less water to replace after. I'm doing more frequent 20% water changes now where before I was doing 50%.