Devlog 2 Hydro Garden - BOM

what i did

swapped the module joints from bolts and heat set inserts to four m5 tie rods running the full height of the tower. tightening the top nuts puts the whole stack in compression, which plastic handles far better than pull out, and it drops 32 pieces to 20 with no soldering iron needed
the rods pass through a ⌀16 boss at each end of every rib instead of a full height hole. a rod in tension cannot buckle so it needs no support in between, and 20mm of hole prints straight where 200mm would wander off axis
added the level sensor riser. the jsn-sr04t has a 200mm blind zone and a full tank only leaves 82mm of air above the water, so mounted flush it would read nothing exactly when the tank is full. it now sits on a 150mm post with a 250mm fill line instead of filling to the brim
finished the bom. every part has a real link, a real price, quantities matched to actual pack sizes, and a column saying what breaks without it. $496.40, about $100 under the tier cap

the first led strip i picked was rgb. four conductors needing three pwm channels, and my board has one channel for lights. the other three are committed to dosing pumps
the second one advertised 1800 leds and turned out to be 29 watts for the whole 5m reel. that’s 5.8 w/m, about 24 milliwatts per led. it would have put 19w across 16 plants and grown pale leggy lettuce. bought on watts per metre instead and landed at 17 w/m
home depot doesn’t sell heat set inserts at all, and their m4 bolts only come in 2 packs of plain steel that would rust in nutrient solution