Why using a gel after the spray?
The gel is highly recommended after the spray because it sticks on the wound for more than 24 ours. Using the spray will kill the bacteria and clean the wound but when the fish goes back in the pond or quarantine tank bacteria in the water can infect the wound again. Using the gel will solve this problem.
It has in this matter two advantages: continuous disinfections and cover the wound so new bacteria can not go into the wound again. Using the gel will give you an other advantage: you only have to take out your fish once a day with liquid disinfections you would have to catch your ‘waterfriend’ two or three times a day, which is to stressful.