Tide is safe for septic tanks and sewer systems.
Tide laundry detergent and other Tide laundry products have been evaluated and are safe for use in homes or businesses that have septic tanks and septic systems.
As long as you're using the recommended amounts and are maintaining your septic tanks and have them pumped often enough the tide laundry detergent and laundry products are very safe for septic tanks.
Even most other laundry detergents and laundry products are safe for septic systems.
Toilet cleaners are also safe for septic systems as longs as you use them in recommended amounts.
Most if not all laundry detergents and soaps have been evaluated and have been found safe for septic tanks and septic systems and should do no harm to the septic tanks or septic systems when used as they are meant to be used.
Some other good laundry detergents besides Tide that are good for when you have septic tanks or septic systems include.
Arm & Hammer Laundry Detergent.
Charlie's Soap Laundry Detergent.
Earth Friendly Laundry Products.
Dr. Bronner's Sal Suds.
Equator laundry detergent.
Amway S-A-8 laundry detergent.
Country Save Laundry Products.
Fresh Start laundry detergent.