You might even want to go a degree or two higher, as thermometers are not always completely accurate. If you are even a tad below 87 without realizing it, you risk speeding up the life cycle of the parasite instead of killing it. I recently treated for ich and kept the temps at 89 with no ill effects.
joy to the fishes in the deep blue sea
55, 30, 30, 20, 10, and 10-gal. freshwater tropical tanks