50,
The myth rests on the principle that your filter is there to prevent algae.. It is not.. it is there to simply capture all the junk that falls into your pool. If you are happy with the way your skimmers are working, than you most likely have run the pump long enough.
You can run your pump for however long you want.. But we do not want you to run your pump just to meet some mythical number.. Run your pump for a reason.. To skim the pool surface, to generate the amount of chlorine you need if you have a SWCG, or tab feeder, or to just mix some added chemicals.
Since you have a VS pump, my recommendation is to run as slow as what works for you.. The whole point of a VS pump is to cut the cost of the old electrical bill.. I run my pump 24/7, at 1200 RPM, most of the time.. My cost to do that is less than $20 bucks a month and I could not care less how may turnovers that is.. I personally like that my SWCG is making a little chlorine all the time, and that I have constant skimming.
Every pool and every pool owner is different.. Just run the the amount of time that works best for you.
Thanks.
Jim R.