Gravel to sand

Question
Hi I have a 55 fresh water tank, It has been set up of a year now, My question is can I change the gravel bead to a sand floor, I'm interested in getting a fresh water stingray, and heard they like the sand, The tank has 1 oscar, 1 red devil, 1 rainbow shark, 1,Algea eater, and a stone/toad fish, The red devil likes to scoop the gravel in it's mouth and spit it back out. They are well feed so I don't know why he's doing that.
 Will the sand cause any kind of ill effects on the current fish.  

Answer
Hi Steve,
   You are right that stingrays really need to be on sand. They use the sand for a hiding place by lying down and covering themselves with a fine layer of it. (it is really cool to watch them do this).  The trouble with sand is that it can be a little harder to work with than gravel.  The big problem is that if the sand is really thick (say 2 inches or so) it will trap organic matter which then rots and isn't good for the tank. But, if you have a stingray in there, the stringray will tend to keep the sand moving.  Plus your red devil will keep the sand moving.  That does raise another question. I have my doubts that a stingray and a red devil will do well together. I suspect the red devil will constantly bother the stringray, possibly to death.  

 The red devil moves the sand around because that this how they make nests/territories: they scoop out the sand from an area.  

 Other than the problem of compaction mentioned above, the sand isn't a problem (except that if your filter intakes are not right you can get sand clogging your filters).

-- Ron
  rcoleman@cichlidresearch.com
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