DOCK LIGHT MAINTENANCE GUIDE
How to Remove Barnacles from Underwater Fishing Lights (Safest Method)
If you’ve ever wondered how to remove barnacles from underwater fishing lights, this guide gives you the safest and most effective method step-by-step—without damaging your housing, seals, or lens. We’ll also show you the only true ways to avoid barnacle cleaning entirely: an above-water fishing light or the purpose-built Mega Series maintenance-free underwater system.
Quick Answer
To remove barnacles from an underwater fishing light, soak barnacle-covered surfaces in white vinegar for 20–30 minutes (or up to 60 minutes for heavy growth), then gently scrape with a plastic scraper or flathead screwdriver. Rinse with fresh water and reinstall. Barnacles can reattach within hours in saltwater, so the only true “no-cleaning” options are above-water fishing lights or a purpose-built maintenance-free underwater system.
Barnacles will attach to anything left underwater long enough—boats, pilings, ropes, docks, and underwater fishing lights included. If you use submersible dock lights or underwater LED fishing lights, barnacle build-up isn’t a matter of if, but when.
While there are ways to slow marine growth—like antifouling paint or removing lights between uses— no method completely prevents barnacles on permanently submerged fixtures. That means periodic cleaning is simply part of owning most underwater fishing lights.
This guide shows you the safest and most effective way to remove barnacle build-up without damaging your light or its seals.
Barnacles are made up of nearly 97% calcium carbonate by weight and 3% organics, per the National Center for Biotechnology Information.
Keeping this in mind, we need something that will break down the calcium deposits. If you’ve ever descaled a tankless water heater or fought hard-water buildup, you know where this is going.
Why White Vinegar Works on Barnacles
Barnacles are composed of ~97% calcium carbonate, the same mineral responsible for hard-water scale. Mild acids—specifically white vinegar (acetic acid)—break down calcium deposits without harming metal housings or lenses when used correctly.
This is the same principle used to flush tankless water heaters and descale marine hardware.
Materials Needed for Barnacle Removal
- 5-gallon bucket
- 2 × 1-gallon jugs of white vinegar
- Flathead screwdriver or plastic scraper
Most underwater fishing lights fit completely inside a 5-gallon bucket using ~2 gallons of vinegar.
We purchased ours from Wal-Mart and they were inexpensive (around $3–$4 per gallon). Photo example:
How to Remove Barnacle Build Up (Step-by-Step)
Step 1: Fill the Bucket
Pour both gallons of white vinegar into the 5-gallon bucket.
If your light is larger, add enough vinegar to fully submerge all barnacle-covered surfaces.
Note: Most underwater fishing lights can be fully submerged with 2 gallons of vinegar in a 5-gallon bucket, but size varies.
Step 2: Submerge the Light
Place the underwater fishing light (or removable component) into the vinegar bath.
Note: The barnacles should be fully submerged. If they are not, add more vinegar.
Step 3: Let the Vinegar Work
Allow the light to soak for 20–30 minutes.
- Light buildup → ~20 minutes
- Heavy barnacle growth → 45–60 minutes
The longer the soak, the easier removal becomes.
Step 4: Scrape Barnacles Free (Gently)
Remove the light and gently scrape barnacles using a flathead screwdriver or plastic scraper.
- Barnacles should pop off easily
- Do not gouge seals or lens edges
If barnacles resist removal, re-submerge and repeat Step 3.
Step 5: Rinse and Reinstall
Once clean, rinse the light with fresh water and reinstall.
How Fast Barnacles Come Back (Reality Check)
Barnacles begin attaching quickly in marine environments. Per the National Center for Biotechnology Information:
- 5–6 hours: organisms can latch
- 16 hours: visible calcium deposits begin
- 48 hours: full mineralized shells can form
This means any permanently submerged light will require maintenance.
How to Slow Barnacle Growth on Underwater Fishing Lights
Anti-Fouling Paint (Limited Effectiveness)
Some marine paints release biocides that can slow growth for weeks or months, but:
- Growth may eventually occur again
- Effectiveness varies by water conditions
- Environmental impact is a concern
Remove Lights When Not in Use (Most Effective)
Removing underwater lights between uses is the only guaranteed way to prevent barnacle buildup.
Heat Is Not a Solution
While heat may reduce growth in some areas, barnacles will still attach to cooler portions of the housing—eventually causing overheating or failure in LED style underwater lights.
The Honest Truth About Underwater Fishing Lights
Choosing an underwater fishing light also means accepting periodic maintenance. This applies to all designs—sealed housings, exposed bulbs, and protected fixtures alike. Anything left submerged will eventually accumulate marine growth.
If you want the underwater look without the underwater cleaning, the best long-term solution is a system engineered to be maintenance-free—like the Mega Series Underwater Green Fishing Light.
While the upfront cost is higher, it eliminates the ongoing hassle of scraping, soaking, and maintenance. Simply put: there is no cheaper underwater option that offers the same “set-it-and-forget-it” performance.
Want a Maintenance-Free Option?
If you want zero cleaning, zero scraping, and zero routine upkeep, your best options are:
- An above-water fishing light (stays out of the water, so barnacles can’t attach)
- A purpose-built maintenance-free underwater system designed for permanent installs without routine cleaning
For a deeper breakdown, we also recommend reading our Guide to Maintenance-Free Green Fishing Lights.
Jump to:
