I have been running in an issue where somehow I get 1001 clean slurry while I should have got 1000. It seems to duplicate in the chemical washer. I tested and for 1000 slurry, I get 1001 clean slurry. I gives me each time x + 1 clean slurry per x not clean slurry.
I'm using EnderIO conduits for gas transportation. Maybe it's linked.

Can't reproduce with and without my pressurized tubes, sorry. Check with EnderIO.