Are you using a filter from Carl or something else? Perhaps some just can't flow or maybe you have bad luck. Looks just like my setup and I've run nearly 6000 gallons through it without a hitch. (knocks on wood)
I don't see a pressure gauge, do you have one to add to see what your pressure is?
42.82N
2015 - Small operation. 25 buckets. One excited 5 year old and one 35 year old that feels 5 again.
2016 - One year older. New Homemade 2x4 Arch, Smoky Lake Pan and looking at 52 maples, 17 box elders and 2 walnut trees.
2017 - Shurflo 4008 hooked to 42 stingy silver maples and a few Norways. A couple buckets on sugars and Norways. 10 box elders.
2018 - ...a few more taps.
2019 - ...more taps on 3/16 gravity. This spiral is heading downward in a hurry.
2020 - 4x400 RO - RB20 (uh-oh!)