Applying a dose on a per-litre basis, as inline water treatment systems do, is not recommended because of the huge variation in daily water intakes.  Depending on the temperature of the day, the dry-matter content of the feed, and other factors such as sunshine hours and rainfall, cows can vary from drinking 10 litres to as much as 70 litres per day.   If water is treated per litre, animals are severely under-dosed on low intake days and overdosed on high intake days.  That is why it is important that the trough is treated on a per-animal per-day basis.  Only the patented PETA Dispensers can meet these requirements.

Treating the trough directly, also saves your plumbing, as none of the treatment material is pumped through the plumbing on your farm