In rec.aquaria.freshwater.cichlids Cookie wrote:
I have been considering for sometime of switching from pea sized
gravel to 1-3 inches of fine sand. It is a 50 gallon long tank with 1
oscar, 4 giant danios, 1 plec, and 1 dragon fish (which would love to
burrow in the sand.) The pet store only has sal****er and Aragamax
Sand. What is exactly Aragamax Sand? Is it intended for FRESHWATER
tanks? Does it contain salt? Would my box filter suck it all up? BTW,
I don't have a UGF installed. Thanks in advance!

I use Aragamax sand (not to be confused with Arag Alive sand, which is
packaged in salt water, same manufacturer) in my rift lake tanks without
issue. My shellies really like to move it around and sift through it. It
seems to be about the right sized grain for their sand digging activities.
I've not had any issues with the power filter during day-to-day
activities, although the sand can get stirred up while refilling after a
water change if I'm not careful, so that's something to keep in mind.

That being said, I'm not sure your particular tank is suited towards
having this kind of sand. It is not inert. It is calcium carbonate and
will break down in the water over time, which will increase GH and KH.
While this is perfect for a rift lake tank, I am not sure how well this
would go over for your oscar. You can find more inert sand like the other
responders have suggested. Or if you're leery about that, for more money
you can probably find a fish store that sells 'plant sand' or, if you want
a different look, there's also black sand. If you have no other options
than the Aragamax or just really prefer it for some reason, I'd say to try
seeing how rapidly it affects your water chemistry first by setting up a
test bucket.