Aquarium mineral deposits and buildup occur in a tank as water evaporates. Mineral deposits can appear as thin white bands on the glass near the water line. Deposits often grow wider as water levels drop. Mineral buildup can also appear on other hard surfaces above the water line. It’s not uncommon for buildup to occur near the rim of the tank, on plastic power filter covers, on glass tank covers and lighting hoods, and on heater suction cups. Mineral deposits growing on these hard surfaces build up slowly, and in someways they form interesting looking colors, patterns and shapes.
Are Mineral Deposits A Problem?
Mineral deposits usually develop over long periods of time and are more of an aesthetic issue as opposed to being dangerous or harmful to a tank. Where mineral deposits become a problem is when hobbyists try to remove them. Its common for new hobbyists to make removal mistakes that can damage their freshwater setups. One of the most common mistakes is trying to physically scrape the hardened, dry mineral buildup off the glass. Hobbyists can scratch the glass or acrylic sides of the tank, and this damage cannot be repaired.
Another common mistake occurs when hobbyists attempt to remove mineral deposits with a paper towel. Hobbyists try to wet the paper towel with a store-bought glass cleaner and then attempt to rub the mineral deposits off the glass without letting the paper towel dip into the tank water. This method is not a good choice. The mineral buildup is too hard to be rubbed off with a paper towel. Also, the paper towel almost always dips into the tank, releasing the glass cleaner into the water. Its very important to keep cleaning chemicals out of aquarium water as they can be harmful or fatal to fish.