Stressed Red Devil

Question
i have a 55 gallon tank with 1 Red Devil and a plocosumas.i
have an Aquq Tech 30-60 filter along with a smaller one.the Red Devil has always been healthy and agressive.the tank has a few plastic plants, some aquarium rocks, and some bigger rocks. after about a week of a partial water change and cleaning the tank turns green and cloudy so cloudy that you can hardly see the fish. i've tried all the products that said it would take care of algea, cloudy water etc.etc. but nothing worked.So i thought it had to be something in the tank.so i syphened the Devils water into another tank, put him in it so i could drain and clean his tank. i made sure the water temp. was the same and tested all the levels ph,nitrate, hg etc..everything was great so i then put him back in it.iwhen i filled his tank back up i had replaced the aquarium rocks with sand  that was for fresh or saltwater tanks and bought a Rena Filstar XP1 cannister filter along the Aqua Tech filter.Devil has not been himself at all.like he's all doped up and out of it.all he does is stare at himself. and the Placosamus has been staying on the bottom of the tank only moving when provoked.
Please tell me what to do to save my fish.
                              Thank You
                               Shelley

Answer
Hi Shelley,
  The biggest cause of algae is too much light and too many nutrients in the water, usually the result of either overfeeding and/or insufficient water changes.  

  Step 1: reduce the amount or duration of light on the tank.  A little difference in light can change the algae growth a lot.

  Step 2: Do regular weekly partial water changes. It is FAR better to change 25% of the water once a week, every week, than it is to change a lot of water at once. Changing a lot of water can shock the fish which sounds like what has happened.

-- Ron
  rcoleman@cichlidresearch.com
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