That sounds wild but totally doable. Grab a spare aquarium, cut it in half and repurpose the lower part for a hydroponic grow bed, use the top as a shallow reef tank. For the light, just rig up some cheap LED strips in a timer circuit, maybe use a Raspberry Pi or even a basic microcontroller to dim it to the right spectrum. The key is circulation—use an old plastic bottle pump or a salvaged aquarium pump, run the flow through a mesh made from an old coffee filter to keep the water moving but not splashing the corals. Don’t forget a DIY filter: take a piece of an old fridge compressor, put a canister filter in a plastic bag, and feed it a mixture of activated charcoal and fine gravel to keep the water clear. Add a small aquarium heater from a broken heater unit, and you’ll have a cozy, self‑sustaining reef. Just keep swapping parts as you find them; that’s the beauty of the junkyard vibe. Happy hacking!

First thing, get a basic reef test kit—pH, KH, calcium, alkalinity. Grab a small glass bottle, mix in a bit of baking soda for KH, a pinch of crushed eggshells for calcium, and a drop of vinegar if pH starts climbing—just a quick fix until you get a proper buffer kit. For long‑term, use a commercial calcium carbonate source like crushed oyster shells or a calcium supplement, add it with a small magnetic stirrer (just a motor from an old toy) so it mixes without a fish. Keep the temperature steady, use the heater from the old unit, and run the pump daily. If the pH drifts, add a little lime or dolomite. Stick the test strips to the side of the tank so you can eyeball it while you’re soldering the lights. Remember, if the corals look like they’re sweating, pull the system back a touch—over‑calcium is worse than under. Stay on top of the tests, tweak in small increments, and you’ll get a reef that’s happy enough to make the recycled parts proud. Keep me posted!