By Donna M. Recktenwalt
You’ve decided to use that old tank that’s been sitting on the back porch for a couple of years, or you’ve just acquired a tank that’s been sitting in someone else’s basement for who knows how long. It’s a mess– not only filthy and cobwebbed, but encrusted with all kinds of mineral deposits from poor care and neglect.
Cleaning off the ordinary dirt is simple: a stiff brush and good hot water will take care of most of it. A chlorine and water rinse will eliminate any unwanted pathogens that may still be present.
But what to do about those unsightly mineral deposits? The first advice from some who have been there is to not use detergents of any kind, since they can leave residues harmful to fish.
The second advice is to use white vinegar and lots of good, muscular scrubbing. It takes work, but usually works pretty well. Just be certain to rinse out the tank well afterwards.
However, sometimes vinegar and good effort isn’t enough. Wright Huntley has used a product called “CLR,” available at hardware stores. This is an acid, “not quite as aggressive as pool acid, but be careful anyway,” he recommends, since it will burn skin and can damage patio cement. Heavy encrustations of minerals can be attacked with a razor blade scraper after softening in the acid.
Lee Harper reports that “Lime-off,” sold in pet stores for tank cleaning purposes, will work, as will Real Lemon artificial lemon flavor, which contains citric acid. “Probably muriatic acid (with appropriate personal protection – rubber gloves and eye protection) or perhaps Cherry Coke (pH about 4.5) would work,” he adds. With any of these materials a single edge razor blade is also required, to scrape off the softened deposits.
If the tank has been used for saltwater, a “haze” may be etched into the glass surface. Unless you were planning to use the tank for display purposes, this poses no problem, although it may result in reduced visibility through the etched areas. In addition, algae growth on the glass in the etched area may be next to impossible to remove.