The softer the toilet paper the more chemicals were used to make it soft. These chemicals can be harmful to your system’s biological activity, just like anti-bacterial soaps and other harsh chemicals are. Pick a brand of toilet paper that is in-between for softness. Look for a brand that is “Septic Safe”. These brands are normally made with fewer chemicals and are better for your septic system. As a reminder, overuse of any paper can lead to blockage in your septic. NEVER flush wipes, even if they are labeled “flushable.”