When you see other freshwater and saltwater fish rubbing and scratching themselves against rocks, wood, plants, gravel, or anything hard, you can pretty much count your unlucky stars because your fish most likely has a parasite. Fish will scratch themselves, trying to remove the source of the irritation. When African Cichlids scratch themselves, another irritation is at play. I have seen African Cichlids at all ages scratch themselves, even a few hours after being released from their mother's buccal cavity, and never have I lost one of these fish to a parasite. What causes them to scratch is usually due to improper water conditions or their being introduced to water with a different set of properties.
African Cichlids require very hard water, on the order of a KH of 14 to 17. Unless the water has a natural buffer, the minerals that make the water hard, will "fall out," or precipitate out in about a week's time. If that happens, your water will slowly become softer than is ideal. This is the number one cause for an African Cichlid's scratching. The second most common is following a drastic water change with a change in temperature, pH, or hardness. Even if you are restoring the water to an ideal pH or hardness, you will observe an increase in scratching for the first hour after the water change. That is because they are having to adjust to the new osmolarity. Their skin will be irritated and their scratching is in attempt to alleviate that discomfort. Ironically, if the water conditions are not brought within ideal ranges and the scratching is allowed to continue, they will scratch their scales right off. Wounds like this often lead to an infection, and if left untreated, death. So, if you find your fish scratching heavily, check your pH and hardness.
