Not too difficult once you get the plan down. I'm at best a novice DIYer, so anyone can do this. Details in my build thread.
TL;DR version: you need (1) mini fridge with compressor that keeps temp at 4 C / 39 F; (2) doser and tubing; (3) drill; (4) T barb fitting; (5) silicone sealer. For food, I use Reef Nutrition Oyster feast, ROE, Roti Feast, Pac Pods, Arcti Pods and Phyto Feast in a 1:3:1:2:2:1 parts ratio (e.g. 3mL + 9mL + 3mL + 6mL + 6mL + 3mL, respectively in. VERY clean 50mL tube).
1. Drill big hole in top of mini fridge for power cord.
2. Drill smaller hole for tubing (mine has 2 holes because one dosing head pump AFR, not food)
3. Set up doser. I strapped mine down to the rack with zip cords.
4. Connect first dosing head to liquid food, cut the cord short, like a few inches out of the doser head.
5. Attach T barb to food line.
6. Connect second dosing head to bigger container of RODI, also cut short.
7. Attach second T barb opening to RODI line.
8. Cut long tube that goes to tank (or sump)
9. Attach long tube to last T barb opening, snake the tube out of the small drilled hole, and attch the other end to a dosing tube holder above the water line (important! We don't want back flush of tank water to contaminate line).
10. Fill in the drilled holes with silicone leaving no openings in order to keep temp.
11. Set up dosing schedule and pump in that food!
