Since I prefer to keep smaller tanks (under 50 gallons) I've only had one Pleco. Based on my brief experience with Plecos, I can say that mine was one of the hardiest fish I have ever had the pleasure of taking care. Mine was given to me by a friend who had a neglected 55 gallon tank. No water changes for months. No heater. Many other fish died in my friend's tank, but not the Pleco. I had the Pleco for about a year. Did many water changes.. Many medication treatments, because I had some
Mollies with the Pleco.. The Pleco made it through the entire time with flying colors. No problem.
On the packaging there are usually warnings about which fish need lower dosages.. For example, on the Quick Cure, for Tetras it is recommended only to use one drop for every two gallons whereas it recommends one drop per gallon for all other freshwater fish. The Maracide contains
Tris (hydroxymethyl) aminomethane and
Dibromohydroxymercurifluorescein(Say that ten times quicker). Quick Cure is basically a type of
Formaldehyde.