Always pre-mix fountain solution in volume to eliminate non-productive trips to the water faucet.
Mix a gallon a single press, five gallons if using multiples.
The most productive (and profitable) multiple-press shops I’ve visited use stackable 5-gallon cube-tainers with dispenser valves to supply pressmen with a pre-mixed fountain solution, a pre-mix for each process and or plate type.
Always keep a ‘full spare’ fountain bottle and cap assembly near each press ready for use. This practice allows your pressmen to switch fountain bottles without stopping/leaving press and prevents the dampener from ever running empty/dry and un-necessarily wasting stock and press time!
If you use kompac dampeners, suck-up and discard spent/contaminated (with paper sizing/fibers) fountain solution every 10,000 sheets or so from both sides of Kompac when changing plates or reloading feeder. This will keep fountain solution fresh and reduce fiber contamination in ink surface of form roller for holding color and producing optimum print quality.