[2] This accumulation begins to show the black stains as the cyanobacteria develop their dark and hard UV-protective outer coating.

Most experts within the subject area conclude the bacteria to be harmful, if left untreated, as the growth holds moisture within shingles causing premature aging, rotting, and/or granule loss.

[citation needed] The buildup of Gloeocaspa magma on residential properties has led to earlier roof replacements, lowered property resale values, insurance companies canceling policies and increased utility costs as the black stained roofing draws in more heat.

Treatment There are many available options for the eradication of Gloeocapsa magma, the most common and most widely accepted solution being an application of sodium hypochlorite[3] as well as copper sulfate.

The preferred technique is a non-pressure application of a properly proportioned detergent mix, as this will avoid costly damage to the shingles.