Yeah I hear it's a bitch to pack the carbon properly to make it efficient. I don't no first hand per say. What size fan filter combo.are you running
4 inch inline fan with a 4x12 phresh filter.
I bought the phresh because they are supposed to be good and had mostly good reviews with people claiming multiple runs on amazon.
I'll pull it off in the morning a lights out and inspect the filter, fan and ducting to make sure its all in good shape.
I have heard its hard to refill without a shaker. I could set it on top of my tiller with it running. Lol.
I reckon refilling works just how long would it last. I've made a couple homemade filters.
If its cheap enough to buy it bulk I'll refill all three and swap as needed.