Coral jail / mushroom box STL generator
Mushrooms walk. Zoas get nibbled. New frags get knocked off the rock. A jail keeps them put while they attach, and ReefCAD sizes it to the job: set the length, width and height and every wall gets openings auto-fit to its face, with the same solid border all the way around.
Free to design · 1 credit per new design · Watertight STL + 3MF
How it works
Your numbers, not ours.
The lid is a separate part with a lip sized from your lid clearance, so it presses on firm and still pops off with the pull tab. The floor can be solid, perforated, or a plug stem that drops straight into a frag rack.
What you can tweak
- Length and width 30–220 mm, height 25–180 mm
- Jail bars, hex mesh, round holes or horizontal slots
- Opening size and bar width
- Solid, perforated or plug-stem floor
- Vented or solid friction-fit lid with a pull tab
- Magnet pockets, suction-cup keyhole, rim hanger, screw-in or PVC pipe legs
Print tips
Print it right the first time.
Dial in the lid with the pegs
The Fit-Test Coupon’s peg and socket pairs step the clearance in 0.05 mm steps. Pick the pair that presses together firmly and still comes apart by hand: that’s your lid clearance.
Size the openings to the coral
Openings smaller than the coral’s base keep it from slipping through while water still flows across every face.
Print the lid like the box
Same filament, same settings as the box and the coupon, so the lid’s lip fits the way the coupon said it would.
Read before you print
Choosing filament for saltwater tanks
What each common filament handles, what to keep out of a reef tank, and the print settings that matter more than the brand on the spool.
Frag plug hole sizes, and why fit matters
Plug stems vary by brand, and printers print holes a little small. Here’s how to find the hole that holds your plugs snug, without guessing.
FAQ
Coral Jail questions.
Holding mushrooms, zoas or a fresh frag in one spot while it attaches, and keeping fish and crabs off it. Water still flows through every face.
The lid’s lip uses the lid clearance from your fit profile (0.25 mm per side until you calibrate). The Fit-Test Coupon’s clearance pegs dial it in for your printer.
Yes. Pick the plug-stem floor. The stem is a separate part shaped like a frag plug and sized to your rack’s hole.
Yes. The box prints upright, the lid prints flipped, and the plug stem prints head-down like a real plug.
More parts
Same fit, different job.
- Water Test StationOne home for your reef test kits.Reef water test station STL generator
Stop buying racks that almost fit.
Your tank, your plugs, your printer. Design it in a minute, print it tonight.