Foggy Fish Tank

Question
We just got a sucker fish for a small 5 gallon tank. (we have 3 goldfish in it). Tank was getting algae so I decided on Sucker fish.  Tank was beautifully clean first 2 days of sucker fish purchase.  No algae left so I bought tablets.  1st night I put one in and fish devoured it.  Next night I put another and there is a hairy film by the rocks and tank is foggy???? Totally confused and don't know what to do.  Should I totally clean tank out, obviously saving some water from old tank with fish and then introducing them back into clean tank... HELP!

Answer
Hi Rochelle,
 It is never a good idea to totally clean out a fish tank. That destroys all the good bacteria as well as any bad bacteria. You are much better to change 25% of the water at a time.  Ideally, you should be changing 25% of the water, once a week, every week.  

 There are several reasons why your tank could have gone "foggy".  It might be that the suckerfish (plecostomus) spat out the algae wafer and it is now rotting in the tank.  Or it could be that he ate it and that put a lot of waste into the tank that the tank wasn't used to.  A fish tank is really a living system and it takes it awhile (the bacteria actually) to deal with new inputs of waste.  So, give it time and do 25% water changes over the next few days.  My guess is that the water will clear up after a week or so.

-- Ron
  rcoleman@cichlidresearch.com
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