Some brands are better than others. A few years ago Karen Chaton did a study/survey on different electrolytes. Check the archives on RideCamp. Less sugar is better. Train with lytes at home so that you know if they have adverse effects on your horse. Years ago riders didn't even know about lytes. Then everyone started giving lytes before the ride & at the lunch stop. In the last few yrs the protocol has gone to every 1 1/2-2 hrs. Now the thought is that this is overkill & more people are moving away from using so much electrolytes. You really need to just know your horse & do what works best for him. Never give lytes if the horse isn't drinking. Be aware the lytes can cause/irritate ulcers. Some people are mixing them in plain yogurt, applesauce, syrup, molasses, pureed carrots, etc, in the hope that this will reduce the risk of ulcers. Plus it makes them more palatable. Personally, I preload 3 days prior to a ride. I give a dose the morning of the ride & then give according to how my horse is doing. If he's sweating a lot & drinking well I'll give him lytes at lunch. If your horse is eating well, a lot of wet hay at lunch will do a lot more than syringing lytes into him. Tell your husband to enjoy his ride.