According to most experts, septic tank treatment is not necessary. Septic tank rejuvenators are said to actually cause more harm to the septic system. Some chemical additives can cause actual damage to the system and render it ineffective.
Components like harsh chemicals or yeast can damage your system. Yeast is an active product and will foam up, preventing the regular settling of the solid masses. It can also cause ineffective coagulating of grease matter. It agitates the solid waste and forces it into the drain field, shortening the life of the system and clogging up the soil. There is a certain level of natural bacteria that is required in the septic system and chemicals like bleach and disinfectant will ruin your system and contaminate the soil and drainage fields.
Certain conditions, regarding the property where the septic system is located, can result in the ‘needed’ bacteria being destroyed by chemical additives. A septic system is quite similar to a finely tuned mini-ecosystem and its own environment can be better for it than unnatural products added. Once you stop putting bleach into the system it is like an inoculation to the system. As soon as the toilet is used it gets back what it needs from the system, to function correctly. Therefore, the conclusion is that treatments are not necessary and will not work as effectively as they lead us to believe.