A great, cheap air filter for those who suffer during the spring season

I have major sinus problems every spring due to allergies. These can get so bad that they turn into a sinus infection.

Out of fear of needing yet another round of strong antibiotics, i did some research online about sinus infections and found this blog and the video here, which shows that this “$25” filter can perform about 90% well as a 900$ filter. Pretty amazing: