Biological additives such as Rid-X, Bio-Clean and Green Pig Solutions receive mostly positive customer reviews on Amazon.com, but research indicates that septic treatment products typically aren't effective and may cause more harm than good. There are two main types of septic tank additives; one is chemical and the other is biological.
Chemical additives are marketed as drain openers and clog removers. They often include corrosive ingredients such as sulfuric acid, which can damage septic systems. Chemicals from these types of additives can also leach into groundwater.
Biological additives like Rid-X and Green Pig Solutions contain bacteria, yeast or enzymes. Customers on Amazon.com praised Green Pig Solutions, noting that the product reduced odor, improved an older sluggish system, and allowed more time between septic clean outs. Several reviews of Bio-Clean noted that the product worked to clear sink drains and reduced sludge in the septic tank. Washington and Massachusetts maintain lists of approved additives that include Rid-X, Bio-Clean and Green Pig, as of 2016.
The U.S. Environmental Protection Agency position on septic tank additives is that they don't work and may cause harm. Some research indicates that adding yeast may lead to rapid gas production and reduce soil absorption. The EPA maintains that biological additives aren't harmful but are unnecessary, while chemical additives are undesirable and can be harmful to the environment.