Red Devil - tank problem

Question
I moved my Red Devil From a 35 gallon tank to a 55 gallon tank last March.  Everything was going well until 2 months ago when he had a bad case of ick.  I had to do several treatments of ick clear.  The Algea would increase greatly after each treatment. I was able to keep that under control until 1 month age he came down with a very bad case of ick.  The pet store employee advised that he had Velvet and gave me a stronger medicine for him made by Mardel.  After using that, his ick cleared up, but the tank became very green. He also appeared to have "holes" in his skin aroung his eyes and head.  As time went on the holes looked more irriated and became red as if they were bleeding.  The Algea treatment I was using did not seem to be helping anymore.My boyfriend became very concered and determined the water in the tank must be the problem.  My boyfriend started doing frequent water changes, every other day, half the tank.  My Red Devil became Listless and started floating at the top of the tank. The holes on his face did not improve and he appeared to be getting ick again.  Yeaterday, my boyfriend did another water change and forgot to add the water conditioner.  When I came home afew hours later, my fish was laying on the bottom of the tank and barely moving.  I added the water conditioner, but he did not improve.  I moved him back into the 35 gallon tank and he improved immediately.  After 12 hours in the 35 gallon tank he is back to his old self. His face even looks better.  I know he needs to be in the bigger tank, but now Im afraid to put him back in there.  What should I do to the tank to make it safe for him to live in again and make the water clear? My boyfriend wants to do a complete water change.  Would you advise that? Also, can you speculate on what went wrong.  I have another 55 gallon ciclid tank that does fine, the fish a healthy and the water is crystal clear.  I don't know how I went wrong with my Red Devil's tank.

Answer
Hi Laura,
 First, one can never do too many water changes. In fact, in some aquarium systems I have had in the past, the water changed continuously.  However, you should not add the new water to the tank and then add the water conditioner.  You should add the water conditioner to the water while it is in a bucket and then add that water to the tank.  Doing it the first way can be really hard on a fish (and can kill it).  

 I have never seen a cichlid with velvet and certainly not a red devil.  Ick yes, velvet no.

 It is weird that your red devil should get ick more than once.  Are you feeding it feeder goldfish by any chance?  If so, stop immediately.  That is where the ick is coming from and to top it off, they don't normally eat fish.  Feed him with cichlid sticks such as Tetra Cichlid Sticks or cichlid pellets.   

 The fact that you have so much algae suggests that you are overfeeding.  Is this possible?  Algae also needs a lot of light to grow. Reduce the amount or duration of light on the tank
and the algae will decrease.  

 Never change all the water in a tank. That kills off all the good bacteria as well as the bad. In general, you should change only 25% of the water at once, though some people push it to 50%.  
You should change 25% once a week, EVERY week.

-- Ron
  rcoleman@cichlidresearch.com
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