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.
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 is not a matter of if, but when.
While there are ways to slow marine growth—such as antifouling paint or removing lights between uses—no method completely prevents barnacles on underwater fixtures. That means periodic cleaning is simply part of owning 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 have a tankless hot water heater and you have hard water, you may already know where we're going with this.
Why White Vinegar Works on Barnacles
Barnacles are composed of ~97% calcium carbonate, the same mineral responsible for hard-water scale buildup. 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 - they are pretty cheap (we paid $3.34/gal) as shown in the photo below.
How to Remove Barnacle Build Up
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: You may need more white vinegar than this depending on the size of your underwater fishing light, or whatever part you are cleaning. We have found that most underwater fishing lights can be fully submerged with 2 gallons of white vinegar in a 5 gallon bucket.
Step 2: Submerge the Light
Place the underwater fishing light (or removable component) into the vinegar bath.
Note: The barnacles should be fully submerged in the white vinegar. If they are not submerged, then add more white 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
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 (Important Reality Check)
Barnacles begin attaching within hours per the 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 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.
The only way to eliminate routine cleaning is to use an underwater light specifically engineered to prevent it, such as our Mega Series Underwater Green Fishing Light. While the upfront cost is higher, it removes the ongoing hassle of scraping, soaking, and maintenance. Simply put, there is no cheaper underwater option that offers the same maintenance-free 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 or a purpose-built maintenance-free underwater system designed to resist marine growth entirely.
For a deeper breakdown, we recommend reading our Guide to Maintenance-Free Green Fishing Lights.
