What's the problem? I don't know what glass surfing is.
You need to provide more info such as tank size, parameters, filter, tank mates (how many, how long have they been in there), how long has it been running, etc.
I moved the 1/2 gallon tank next to him and he stopped. Thanks for the help
Glass surfing is stress in which a fish slides along the glass away from tankmates. It is a 10g tropical freshwater, a topfin filter, 6 guppy tankmates and 1 other tetra, tank running for 10 years.