Step-by-step response
Minute 0-2: Stop the flowDrain water below the leak level using a siphon or bucket. Lower water 4-6 inches below the leak point so it stops dripping.
Minute 2-15: Save livestockMove fish + invertebrates to an emergency container (5-gallon bucket with tank water + air pump if possible). Net coral/snails into temporary holding.
Minute 15-30: Protect floorsTowels around tank base. If wood floors: lift tank slightly with shims to drain moisture, run a fan for 6 hours.
Hour 1: Diagnose leak sourceFind the leak point - silicone seam (most common), corner crack, hairline crack across glass. Mark with tape. Photograph for warranty claims.
Hour 2: Decide repair or replaceSilicone seam fail: re-silicone (DIY $20, professional $200). Hairline crack across glass: REPLACE TANK. Corner crack: re-silicone may work but tank is structurally compromised.
Day 1: Set up emergency tankUse a spare tank, plastic tote, or cycled QT tank to house livestock for 1-2 weeks. Match parameters to home tank.
Day 7-14: Repair completedAfter silicone cure (full 7 days for new applications), water-test the tank with plain RODI for 48 hours BEFORE moving livestock back.
FAQ
Can you fix a leaking aquarium?
Silicone seam failure: yes, drain the tank, scrape old silicone, apply aquarium-grade silicone (NEVER bathroom silicone - mold inhibitors kill fish), cure 7 days. Cracked glass: replace the tank.
How long does aquarium silicone take to cure?
7 days for full cure. 24 hours for surface dryness. NEVER fill before 7 days.
Is bathroom silicone safe for aquariums?
NO. Bathroom silicone contains mold inhibitors that leach into water and kill fish. Use 100% pure silicone aquarium sealant only.