Product review (1 stars): Filters-Now specific
I purchased five filters from Filters-Now, but the delivered filters did not fit in the V3100. I emailed Filters-Now and they claimed that their manufacturer made an error and agreed to send me five replacement filters. I asked for an estimate and waited. A week after the estimated day passed, I emailed them asking for an update. They did not respond so I filed a claim on Amazon against them. The next day, they emailed me saying that they finally received a correct batch [of filters] from the manufacturer and were now submitting orders for them to be shipped.

The first set of 5 filters that I received were too tall and narrow (the circumference was too small). I tried modifying one of the filters so that it would fit. After using the modified filter for about 12 hours, the air coming through the filter contained a strong foul odor.

The replacement set of 5 filters was a bit wide but could be forced into the filter slot of the humidifier. I have not tried using one yet, but I do not think that they would be any better.