Will treating fish for ick hurt a pleco

Question

someone told me it would

Answer 1

Only if you add salt it could hurt them

Answer 2

Plecos are considered "scaleless fish" and many of the standard ich medications are harmful to scaleless fish.  Plecos are also sensitive to the use of salt in their water.  If you are using an ich medication, check the box and see if it says not to use it with scaleless fish.  If it does, you don't want to use it with your pleco.  Either move the pleco to another tank or container for the duration of the treatment, or treat the affected fish in a hospital tank.  It's generally best to use a hospital tank to treat sick fish anyways, especially for ich, as the medications used can also kill or damage the beneficial bacteria in your tank.  

Turning up the heat as high as possible is helpful in the treatment of ich as it speeds up the life cycle of ich and kills it quicker.  Ich is a parasite with 3 stages of life.  The 1st is a cyst, the 2nd is the parasite that lives in the fish and the 3rd is a free floating stage that reproduces.  Only the 3rd, free floating stage is vulnerable to medication, so by turning up the heat, you make the ich become vulnerable to treatment quicker.  Also, if the ich cysts hatch and don't find a fish to live in soon enough, they'll die, so high heat helps get rid of ich in empty tanks sooner as well.

Answer 3

Plecos are sensitive to some treatments, including adding salt to the water.  The best thing to do is simply raise the water temp to 82 degrees F and leave it for a week.  This works better than any med and is safe for most fish.