The Natural Philosopher wrote:

The biodisc is completely free of whiff. I only emptied it because one
day it DID smell and I took the top off..and the pulley had fallen off
the motor. .the man emptied it. washed it, refitted the pulley and had a
nice cup of coffee and a chat. and it cost me IIRC £75quid..


Ok it was about £5k to install, but it got rid of a large eyesore and
now I have a smaller eyesore :-) Been utterly delighted with it. I DO
shove all sorts of chemistry down it, from the chemical toilet in the
camper, to caustic soda to clean blockages to brick acid to remove
plaster scale when I have chucked THAT down the loo as well. It takes it
all. There is enough water flowing through to essentially neutralise the
lot after a day or so.

It smells a lot less than e.g. the Cambridge sewage works, that I used
to work nearby.

I've got an Entek biotek, which is a three tank plant that circulates
the foul water by air through a filter bed. Very effective even though
20 years old. Had an enviro agency check on the output a couple of years
ago. I think having a treatment plant is far better if you can afford it.

Peter Scott