This is a question we often receive from people looking to purchase a sewage treatment plant. If you’ve already read our post on how a sewage treatment plant works you will understand that the process in a sewage treatment plant is a natural biological one.
To try and answer this question, an analogy may help: Do you need to top up your gut with bacteria? Ideally the answer is no, naturally forming bacteria in your gut helps to digest food. This is no different to inside a sewage treatment plant. However, some people take pro-biotics to improve their gut flora. This is something people do when they think something is wrong.
Inside a treatment plant, naturally forming bacteria normally do a good job at cleaning the waste. If you feel you have to add bacteria then this is usually because something is wrong (smells or poor quality discharge). In the event there is something wrong, it is better to work out the cause and deal with that, adding bacteria could help, but it would then be something you have to do constantly. Maybe there has been something put in the water that has killed off the bacteria? Or there is too much waste going through the treatment plant – consider reading what not to put into a sewage treatment plant.
Another common question is “do I need to add bacteria at the start of my treatment plant?” The answer here is no. The bacteria will grow itself and there is no need to “seed” the system with bacteria at the start. It can take 4-6 weeks for a system to get fully populated with bacteria, this is normal and it is ok to use your system immediately.
If you want to reduce the time it takes for bacterial growth then you should try and be kind to the micro-organisms by making sure you don’t use bleach and too much detergent in the first few months.