Elaborate: Only use whole packets. Dealing with open partially used powder packets is just asking for trouble.
Open powder packets are a huge hassle. Maybe you don’t mind hunting down a ziplock bag or a bag clip to hopefully keep the powder contained. This powder has had a taste of freedom and will stop at nothing to get as all over the place as possible at its soonest opportunity. Powder might get all over the container you keep your Gatorade supply leading to moisture finding its way onto all of the unopened packets creating a sugary goo which could attract hummingbirds who will inevitably peck their way into the other packets to get to the sweet sports nectar which will cause them to pass out or die due to a severe electrolyte imbalance and everyone will be depressed upon seeing the pile of hummingbird corpses that has formed next to the drink station. So if you insist on dealing with partial powder packets I suggest you invest in a small shovel. Don’t use a spatula from the kitchen, that’s terrible.
It’s easier just to use a whole packet and be done with it. No muss, no fuss, no dead hummingbirds.
There are basically two situations when you’ll need to make more Gatorade: the cooler is empty or there’s still some Gatorade left in the cooler. In either case, you should only make as much Gatorade as whole packets can make. Variables to keep in mind are how much Gatorade is left and how many coolers do you have.
I’ll start simple. One 10-gallon cooler, empty. Make seven gallons (or more depending on the flavor) and you’re done. “But then you’ll have to make the next batch sooner!” Even sooner than you think. Four gallons are consumed leaving three gallons in your cooler. Throw in another packet and make another seven gallons. Now you’re topped off at 10 gallons and can turn your attention elsewhere for a while. Best of all, you didn’t have to deal with a partial powder packet.
Add more coolers and the math is the same. Every pair of 10-gallon coolers you can use three whole packets. Odd cooler out you treat like the lone cooler in the above example. Use a whole packet to fill up whenever one of the coolers gets down to two or three gallons. Rinse and repeat. Literally rinse out the coolers whenever they’re empty, if not full on wash them.
At this point you might be wondering, “how am I supposed to get the flavors right if I use three packets to fill two coolers?” I’ll address that and more next time when I talk about color mixing.