Help eliminating Iron from my hot tub

I'm a relatively new hot tub owner. I'm on my second refill after purchasing the hot tub about 6 months ago. One thing I've been having a difficulty combating is iron. I'm filling it up from a well that does not go through a water softener. I am using two EcoOne hose filters combined to help with the hard water. I also use an entire 16 oz bottle of Metal Gon when filling. It seems to work fine for about the first 6-8 weeks. Then after that I notice the filter starts to get really...

Help eliminating Iron from my hot tub