The episode was created in 1997, but did not air until 1999 when Nickelodeon picked up the series.
"Reef Blower" is the only episode in which no one speaks.
In the pilot, Mr. Krabs first refers to Squidward as "Mister Squidward". In the regular episodes that follow, Mr. Krabs simply calls him "Squidward", without the "Mister".
"Reef Blower" has no dialogue because it would have been about $5,000 extra to add it in to what was pretty much supposed to be 3 minutes of filler.
In "Help Wanted", Squidward's skin is much paler than it is in later episodes.