Do Septic Tank Treatments Work? What the Bacteria Can and Can't Do

What septic treatments are

Most biological septic treatments contain selected bacteria, enzymes, or both. Enzymes break large molecules such as fats, proteins and starches into smaller pieces, and bacteria then digest those pieces. Chemical additives that claim to dissolve sludge are a different category and can harm the tank's biology or the absorption area.

When treatments can help

Biological treatment is most useful when the resident bacteria have been knocked back. Typical situations include:

• After a course of antibiotics or heavy use of bleach and disinfectants in the home.
• After a pump-out, to help the bacterial population re-establish.
• When a holiday home or property has been unused for a while.
• When there is a high fat or food load, such as a household with heavy cooking.
• When odour is linked to the tank turning septic rather than a physical fault.

When treatments won't help

No product can fix a mechanical or design problem. Treatment will not help with:

• A tank that is full and overdue for a pump-out.
• Broken, blocked or collapsed pipes.
• A saturated or failed absorption trench.
• Inert material such as grit, plastics or wipes, which bacteria cannot digest.
• Systems that are undersized for the household.

How to choose a septic treatment

Look for a product that names what it contains, explains how it should be dosed, and is suitable for your system type, including AWTS where relevant. Be cautious of products promising that you will never need to pump out again. Check the product's Safety Data Sheet (SDS) so you know how to store and handle it.

Aquativ's biological products are designed for Australian septic tanks, AWTS and commercial systems, and the SDS for each one is available on our Safety Data Sheets page. If you want advice for your property, send us your system type and what you are seeing.