Frequently Asked Questions


  • How much does a Matrix cost to run?
  • It costs about £50 - £60 per annum for a 6-12 person.
  • Our house is a holiday home, what happens if I turn the tank off ?
  • You can turn the electricity off and the bacteria will take about 1 week to die. Similarly when you return it’ll take about 1 week to create new bacteria in the Matrix. However, as mentioned above the annual cost is quite low so it may be worth considering keeping the tank running during periods when the property is not occupied.
  • What happens if there is a power cut?
  • The Matrix will happily go for 2-3 days and over 1 week before all the bacteria are dead. So as long as there isn’t a long term issue with the power supply then there shouldn’t be a problem.
  • How long would it take for a tank to be fully operational with bacteria?
  • Once the tank is operational it takes approximately 1 week for it to work at full capacity and for all the bacteria to be present
  • I wish to install in France. Do SPANC have to agree to all installations?
  • For full details on France, please visit our site www.microstationfosse.com 
  • Why don’t more people choose a Matrix over a traditional septic tank?
  • We ask ourselves that all the time! Sometimes it is that customers and in particular their installers are unfamiliar with the systems - the ease of installation reduces the installers profit! There is still the belief that treatment plants are costly and expensive to run. This is based on some of the original systems that relied on moving parts. This is not the case and most treatment plants overall are usually cheaper to install and run than the standard septic tank.
  • How clean is the grey water that exits the Matrix ?
  • The grey water out of the Matrix has a BOD of 96.2%  - that’s 2.6% above the EU recommendation. We’re proud to distribute such an efficient sewage treatment plant, to see the Matrix certificate please go to the Technical & Certificate and Download page.
  • How do you install the tank?
  • All tanks are easy to install as the Matrix has a flat bottom. The tank should be positioned on a concrete base and then backfilled with a lean concrete mix. For full installation details can be found in the Download section on this site.
  • When does the tank have to be emptied?
  • It depends on how much use the system gets - for a full family using the system in a main residence, then the system should be emptied annually. If the system is used infrequently, in a holiday home for example, then every 3 -4 years maybe sufficent.  
  • Should I put extra bacteria inducing sachets into the tank on a regular basis?
  • It is always a good idea to maintain the tank and ensure that there are enough bacteria. We can provided a suitable product, which is based on natural seaweed on request.