Bests & Worsts Reviews from Amazon

I've wanted a shower filter for quite some time. My son has asthma and I wanted to eliminate any pollutants that would aggravate his condition. I was offered the opportunity to receive this showerhead filter in exchange for my honest opinion. Well, I can do that. I waited excitedly for my Amazon box, then ran upstairs to install the filter. Unfortunately, I needed a wrench to take our showerhead off first. Ugh! Ok, the filter is installed and the water smells like hotel water. I'm probably smelling nothing for the first time. So, I wonder, how do you know that the filter is working. My teacher brain kicks in and I start researching shower filter. Based on what I've learned, I will give you my pros and cons list. Pro: No change in water pressure Con: Has a downflow design (upflow design reduces clogging and gives more shower height) Pro: KDF 55 Filter (highly effective at chlorine removal) Con: No activated carbon (reduces trihalomethanes-a byproduct of chlorine disinfection that can produce breathable contaminates such as chloroform. Pro: Contains Crystal Quartz-extends the life of the filter, Con: Not NSF certified, I could find no testing data water softener, catches sediment in the filter URGENT UPDATE 3/19/16: We continued to use the filter, since I agreed to test it out. A few days ago, the casing cracked open, literally blowing the contents of the filter all over my husband.