The patent-pending Hayward Valves allows you to draw from individual tanks of  pure products and proportion them to your individual desired mix.
 
Need a 20% mix on the roof and 5% on the house that’s no problem simply set your mix ratio and, when you need to change it, turn the valve. Never again will your mix be too strong or too weak, the Mixing System will allow you to adjust your mix on the fly. The system works on the inlet side of your pump system.
 
3 way Hayward System is compatible with:
12v Pumps
Air Diaphragm Pumps
Booster Pumps
and many other on demand pump systems.