What’s Causing The Black Stains In My Toilet Bowl And Tank?

If you’ve ever taken off the lid to your toilet tank and came across what looks like black water or staining, it’s probably taken you by surprise. Or, maybe you’ve noticed black or dark staining inside your dishwasher or shower. In any case, these stains are unpleasant to look at and even more of a nuisance to remove.

Chances are these issues are caused from a mineral in your water called manganese. Seeing manganese stains from your water isn’t an emergency, but at high levels, it can have an effect on the quality of your drinking water, laundry, appliances and plumbing. Manganese minerals can leave deposits that build up in your plumbing, restricting the flow of water over time.

But there is much about manganese that is still unknown. In our diet, it is a common nutrient or supplement that we need to survive.

Recently, Health Canada released two guideline values for manganese in drinking water to help protect the health of its citizens. In the U.S., the EPA and various states also offer health-based guidance to educate people on the long-term risks to their nervous system that may be caused by consuming elevated levels of manganese in their drinking water.

How Does Manganese Get Into Your Water?

Manganese is one of the most abundant metals in water and soil and is even present in various foods that we eat, like nuts, beans, and oatmeal. It is an essential nutrient and, in small doses, helps support our health.

However, in parts of the U.S. like the Midwest, there are elevated levels of manganese in the soil, which can find its way into both municipal tap water and well water. Homeowners with manganese in their water will experience staining throughout their home and may also notice an earthy, dirty or metallic taste to their water.

U.S. areas of elevated manganese in the soil. Image courtesy of University of Nebraska – Lincoln

High levels of manganese will also eventually build up in your plumbing and create issues for water heaters and water softeners, which may result in additional maintenance and a decreased lifespan.

The Challenge of Removing Manganese from Water

Manganese is difficult to filter from water because removal depends on its state of oxidation, the pH of the water and the presence of other minerals in the water being treated. Since it often appears along with iron and hydrogen sulfide, removal can be challenging.

For these reasons, it’s important to consult a water treatment expert. Many homeowners may think a standard water softener can solve their manganese issues but it’s unlikely it will adequately remove enough of it. In fact, manganese can foul the softener resin and damage the resin bed, requiring more frequent backwashing putting extra stress on the equipment.

Depending on what the water test results reveal, a more effective solution would be a true iron filter, because chemically, iron and manganese elements are very similar. Another solution would be a water conditioner that utilizes a manufactured zeolite called Crystal-Right^®. This multi-tasking media, exclusive to Water-Right, removes iron, manganese, and hardness in a single pass and also balances pH levels of acidic water.

When it comes to drinking water, a homeowner may also assume a reverse osmosis system will remove manganese. However, high levels of manganese without the proper filtration before the water reaches the R.O. system, can cause plug up the R.O.’s membrane system very quickly, shortening the life of the equipment.

Testing Your Water for Manganese

If you suspect an elevated level of manganese in your water, the best way to diagnose your problem is through a comprehensive water test performed by a water treatment professional.

Based on the results and levels of contaminants, an expert can advise you on the most effective treatment solution and install the proper equipment to treat your home’s water.

Trust a Water Treatment Expert

Authorized Water-Right dealers can help you with your problem water needs, from offering comprehensive water testing services to a variety of water treatment equipment to provide your family with the best water possible.