Fish thats best for cleaning a freshwater tank

Question
Dear Ron Coleman
When ever i go to the pet store i ask for a fish that will do a good job cleaning the tank,they all say get a catfish.I got one but all it does is it eats the food.Is there any fish that will clean the fish tank with out eating the food. I want it to clean the dirt on the bottem not the algae.I also have a 30 gallion tank and a bunch of fish so how many do I need? One last question is there any easier way to clean the tank because I take out half the water every mounth and becomes a hard ack.Thank you so much for taking in my answer and helping me.bye

Answer
Hi Alex,
 There is no fish that is going to clean the tank for you.  Catfish like plecostomus will eat algae but you still have to clean the tank -- that is part of keeping a fish tank.

 The best way to clean a tank is to use a gravel siphon to clean the gravel.  Ideally you would do this once a week, and remove 25% of the water, replacing it with clean water.  

-- Ron
  rcoleman@cichlidresearch.com
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