How to dose per tank?

Groen varen: Solbio Marine – 1,6L | Mobile & cassette toilets, waste-water tanks, ...
40 ml
=
0 - 20 l
80 ml
=
to 40 l
100 ml
=
to 60 l
120 ml
=
to 80 l
140 ml
=
to 100 l
160 ml
=
to 120 l
180 ml
=
to 140 l
200 ml
=
to 160 l
220 ml
=
to 180 l
240 ml
=
to 200 l
260 ml
=
to 220 l
280 ml
=
to 240 l