Is french Domestos ok with Fosse Septique

6 Replies

Hi Can anyone tell me if French Domestos which I bought in Leclerc is OK for putting down the loo and won't affect my fosse septique which takes the sachet's of sand once a week.  On the bottle of Domestos is says sans dangereux pour fosse septique so I'm assuming it won't stop the bugs from doing their stuff in the fosse. ThanksM & D

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honeybuzzard 1126106076

Anything which says "sans dangereux pour fosse septique"  is safe to use.

luce-386189 1126113176

See my previous posting and the helpful replies.  Can I just say that my life has completely changed since discovering I can use Domestos down the loos and sinks!!!!!!!!!!!!!!!!!!!!!!! ;)))))))))))))

tessa-382896 1126115012


I use Tarax which is used every 6 months and allows you to use all bleaches and also stops awkward questions of visitors who may be taking antibiotics as Tarax enables such users not to affect the fosse mechanics.

Also easier to use every 6 months and not that costly either!!!!!!!!

dept 56 near Gourin

Pandora29-388840 1126115553

Good moaning Tessa

Thanks for the info on Tarax, great news in view of loos and visitors and such..... You probably saved my life as some are very fussy and think we live in the pits just because of fosse septiques

Have a nice evening

The Box

Alison35-385907 1126139550

The posting originally from luce prompty me to actually read the back of a UK pot of Domestos, the UK version also says OK for septic tanks.

Though...........anything thats s'posed to kill all I always treat with caution with fosses.  The balance of the fosse is delicate, there's also no real need to chuck chemicals down the sink. 

After all there's several PLC's out there who are telling us to drink "good bacteria", now I'm not saying go drink your fosse, but some bacteria is good.

Personally only use it for any stains that occur (sorry if your eating your tea right now), by stains I mean coffee, tea (kitchen surfaces) or grouting in tiles, even then I'm extremely careful not to let it down drain, but wipe it up in a bucket and sling it the garden.

Shall I tell y'all a funny story....................

10 years ago my ex sent a MASSIVE bouquet of flowers to me several months after I dumped him (wanted to make amends), my then new man with feet under the table put bleach in every one of the vases when I was out, guess what, far from killing them the flowers loved it and sprung into action even more albeit smelling ike a swimming pool.

Still, why out bleach down the loo anyway?


Ille-et-Vilaine (35)

MCM-388973 1126281674

Septic tank performance and cleaning products


Bacteria’s who can resist to antiseptics and chemicals are dangerous to mankind 2 well known bacteria resisting to antibiotics are

MRSA (the super bug can kill people we a weak immune system)

Tsar (chicken flue currently creating havoc in the far east and forcing government to stock pile antibiotics should it spread to Europe  and over part of the world).

The last thing humanity need is any type antibiotics resistant bacteria developing in any kind of waste water system.


Product to maintain septic tank

Thankfully and contrary to popular belief bacteria does not resist bactericides, antibiotics and antiseptics, if they did then even the common cold would be a threat to humankind.  The bacterial fauna of your waste water system will grow according to the quality of their environment and the quantity of food available.

If a company had developed a formula where by the bacteria introduce in a wastewater could resist to bactericides, antibiotics and antiseptics then you would not have poor another dose every 6, 3 or 1 month the bacteria would not have any predators and would simply grow according to the level of food available to them.

If such product existed every single company involve in wastewater treatment would stop spending millions  every years and just go to their local supermarkets and buy a few box of the stuff for pennies!

As for the product, it would become on the most famous brand in the universe.


Cleaning Product

Any body who purchase a product to disinfect their toilets, bathroom kitchen floor and work surfaces does so with the intention of killing germs and bacteria’s.  Now, to the best of my knowledge, there is not one single company in the world who has developed a product capable recognising nasty bacteria in your toilets from good bacteria in your septic tank.

The manufacturer of the product is rightly telling you that if you use the recommended dose, this product will not effect your system. No manufacturer in the world can guarantee that the cumulative effect of several doses of various products will not have an impact on the bacterial fauna of your waste water system.

For example:

A wine producer could say if you drink one glass of my wine, you will not break the drink and drive limit. However, the same wine producer cannot say that you will not break the drink and drive limit if you drink one glass of his wine together with a number of alcoholic beverages.


The damage caused to a septic tank can be expensive to fix. If the tank itself gets blocked then pumping, it will cost few hundred euros. If your filtration system gets blocked then the cost can rise to thousand euros.

The cost of installing and maintaining a wastewater system be it MWWTP or septic tank is substantial and with the new regulations coming into force on the 1st January 2006 it is very likely to get more expensive.

Our advice is very simple

When you are unwell, you visit a doctor, when you need financial advice; you go to visit a professional.

Please follow the same principal when it comes to your wastewater system in the end it will not only save you money but also inconvenience.


If you would like free information on this topic, please do not hesitate to contact MCL.

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