Clarify sand for me.
Do you mean 'playsand', which is extremely fine? Or do you mean something like 'filter' sand or sandblasting grit. Both these last can come in a range of sizes.
I don't think that I posted in Dwane's post, but I think I remember it and the issue of fine sand causing anoxic pockets came up. This is a possibility with playsand, not so much with 2-3mm diameter filter sand or sandblasting grit.
Just a few weeks ago I finished changing my crappy aquarium gravel over to #2 mesh filter sand. It made a world of difference for planting/pruning/moving the stem plants.
I did it stepwise so that I was never taking too much out at a time. I diveded my 10g tank in 2 halves, you may wish to split yours up more.
I vacuumed the half I wanted to work on thoroughly, getting as much of the mulm as possible. Then I thinned it out so that there was about half the depth left on that half of the tank.
At the next water change I again vacuumed the same half carefully (all the while not entirely neglecting the other side) and removed the rest of the gravel using a large fish net. I found it scooped to the bottom of the tank better than my fingers. Then I added the very carefully rinsed sand.
Repeat on remaining fractions.
There was a bit of cloudiness right after adding it, but it settled in less than an hour. Now my tank looks much better, IMO. There are still a few pieces of the old gravel left which I couldn't grab, but that's ok.
I could probably have been a little more aggressive, but I wanted to make certain I didn't upset the balance I've got in my tank right now/then.
