I have no opinion on the Phresh filters, I did just look at them mostly to see their cost. Knowing that they will only work so long before they need to be replaced I focused more on the CFM when I first looked at getting one for my room. One I bought was a Hydro Crunch 6 in. x 12 in. Carbon Charcoal Air Filter with Flange 400 CFM Exhaust from Home Depot for under 60 usd. It worked well through my first 3 grows, but by mid flower of 4th grow it smelled as nice in my back yard as it did in the grow room. I used the 1st filter continuously through the 3 grows. I just replaced it and through this filters life I will only use it when odor of flowering needs controlling to see I can extend it's life cycle. I will say if I only need to spend 60 every 1 1/2 ta 2 years to control odor it is affordable. Hopefully a member has used a Phresh filter and will relay info on it's odor control and life cycle to help you make an informed decision.