What is causing the cement tank to crumble?

According to the Home Adviser the simplified answer to how this happens in the septic tank is that hydrogen sulfide gas is generated by sulfate bacteria that are breaking down the organic waste in the septic tank as a part of the anaerobic digestion process. It is a colorless chalcogen hydride gas with the characteristic foul odor of rotten eggs. It is very poisonous, corrosive, and flammable.
It is natural in the environment but unfortunately some nationally advertised septic tank treatments actually encourage its growth. Once the process is started the damage cannot be undone, but further damage can be stopped by adding TankTechsRx for Septic Systems. Our blend of bacteria will destroy the sulfate bacteria and end the problem. It is best to stop it before it starts.
It’s a real problem, just google hydrogen sulfide in septic tanks to find tons of articles or better yet, just order a liter of TankTechsRx for Septic Systems right now and get rid of the possibility of it damaging your tank.