Maintenance additions of Ferolin should be made pro-rate to the boric-acid additions.
Normally, 1 litter Ferolin should be added for each 5 kg. Of boric acid. This will maintain
the Ferolin concentration in solution at about 8 ml/l. Higher addition rate of Ferolin can be
used if required (up to 3 litters per 5-kg. boric acid).