Fiberglass pools are known for durability and low maintenance. But that doesn’t mean you don’t need to clean them.
If you don’t clean your fiberglass swimming pool, your pool water can get cloudy, oil rings might set, and if it gets bad, there might be some mineral scaling.
But there is some good news. Fiberglass pools are easier to maintain compared to concrete or vinyl-lined pools, as long as you understand their unique surface and how to clean them correctly.
In this guide, we’ll walk you through exactly how to care for your fiberglass pool: from basic cleaning routines and gentle tools to stain prevention, water chemistry, and when to call in the pros.
Cleaning A Fiberglass Pool Is Actually Easier Than Other Pools!
Compared to concrete or vinyl, fiberglass pool cleaning is much simpler.
You don’t need to scrub hard because fiberglass pools have a smooth gelcoat layer.
This layer is the reason why fiberglass feels soft on your foot. It also makes your pool absorb less heat and resist algae growth.
But you have to be careful when cleaning a fiberglass pool. Because you don’t want to scratch and damage this protective layer.
Next, let’s discuss the tools to safely clean a fiberglass pool.
Tools You Need to Clean a Fiberglass Pool (and What to Avoid)
Tools You’ll Need To Clean a Fiberglass Pool:
- Pool skimmer net
- Soft-bristled pool brush
- Microfiber cloths
- Pool-safe sponges
- Magic erasers
- Manual or robotic pool vacuum
- Vitamin C tablets
- Fiberglass-safe pool cleaner
- Water testing kit
Avoid Using These:
- Steel wool
- Stiff or wire brushes
- Pumice stones
- Harsh chemical cleaners not labeled for fiberglass
How To Keep Your Fiberglass Pool Always Clean
Skim the Pool Surface
Use a pool skimmer net to remove leaves, insects, and floating debris from the surface. Do this every few days to prevent buildup and staining.
Brush the Pool Walls and Floor
Use a soft-bristled brush or sponge to gently clean the walls and floor of the pool. Avoid using wire brushes or anything abrasive, these can scratch the gelcoat.
Spot Clean Stains Gently
For small stains, press a vitamin C tablet directly onto the spot for a few minutes. The ascorbic acid lifts organic and metal stains without harming the fiberglass.
Use a Pool-Safe Cleaner Chemical (If Needed)
If brushing doesn’t remove buildup, use a non-abrasive, fiberglass-safe pool cleaner. Apply with a sponge or soft cloth and rinse thoroughly.
Vacuum the Pool
You can use a manual or robotic pool vacuum to clean the bottom of the pool. This removes dirt and debris without the need for harsh scrubbing.
Check and Balance Your Water Chemistry
After cleaning, test your pool’s chlorine, pH, alkalinity, and calcium hardness levels. Balanced water helps prevent future stains and scale buildup.
Check your water chemistry at least once a week.
Wipe the Waterline
Use a magic eraser or sponge to wipe around the waterline weekly. This prevents the buildup of body oils, sunscreen, and other contaminants.
Step 8: Clean After Heavy Use or Storms
After parties, heavy rain, or windstorms, give your pool a quick clean. Skim, brush, and test the water to keep everything in check.
How to Maintain Water Chemistry for Fiberglass Pools
Your pool water chemistry is the first defense against cloudy water, stains, and calcium scaling. Use test strips or a digital test kit at least 2–3 times per week, especially in hot weather or high-use periods.
Ideal water chemistry levels for fiberglass pools:
- Chlorine: 1.0–3.0 ppm
- pH: 7.2–7.6
- Alkalinity: 80–120 ppm
- Calcium Hardness: 200–400 ppm
- Cyanuric Acid (Stabilizer): 30–50 ppm
Poor water chemistry can:
- Trigger metal stains (from iron or copper)
- Cause scale buildup on the gelcoat
- Accelerate gelcoat fading or discoloration
Good water flow is essential, too. Run your pump and filter for 8–12 hours a day to circulate chemicals and prevent stagnation.
How To Remove Stains On Fiberglass Pool Safely
| Type of Stain | Cause | Appearance | Common Locations | Removal & Prevention |
| Organic Stains | Leaves, dirt, algae, body oils | Brown, green, or yellow marks | Corners, steps, flat surfaces | Skim and brush regularly, use vitamin C tablets or fiberglass-safe cleaner for spot cleaning |
| Metal Stains | Iron, copper, or manganese in pool water | Reddish-brown (iron), blue-green (copper), black/purple (manganese) spots | Pool floor, walls | Spot treat with vitamin C tablets, use metal sequestrants, and test water regularly |
| Calcium Scaling | Hard water or high pH/calcium levels | Chalky white or grayish rough patches | Waterline, steps, near return jets | Use fiberglass-safe scale remover, soft sponge, or magic eraser, to keep water chemistry balanced |
How to Close and Open Your Pool Properly
Seasonal pool maintenance is also important. How you shut down or restart your pool affects everything from stain risk to water quality.
To close your pool:
- Balance your water chemistry
- Thoroughly clean and vacuum the pool
- Lower the water level below the skimmer
- Cover the pool tightly
To open your pool:
- Inspect for any surface damage
- Refill and shock the water
- Test and adjust chemical levels
- Clean all surfaces before use
Skipping steps during closing or opening can invite stains, algae growth, or even gelcoat damage.
If you want more tips and a detailed guide, check our other blog: How to Remove Water from Your Pool Cover & Keep Your Pool Safe This Winter. It’s packed with simple tips to protect your pool all winter long.
When Should You Call a Pool Professional?
If stubborn stains won’t come off, your water chemistry seems impossible to balance, or you’re just not sure if you’re cleaning your fiberglass pool the right way—it’s time to call in the experts.
At Sutton Pools, we specialize in fiberglass pools and proudly serve Clarksville, TN and the surrounding areas. When you reach out to us, we’ll:
- Identify and safely remove tough stains
- Help you get your water chemistry back on track
- Inspect and restore your gelcoat if needed
- Provide seasonal checkups to prevent future issues
- Even walk you through DIY maintenance tips if you want to learn more
Not sure where to start? Just call us for a consultation, we’ll give you expert advice and a 100% free quote to help you move forward with confidence.
Let Sutton Pools keep your fiberglass pool looking beautiful and running perfectly, season after season.
Summary: Key Takeaways for a Trouble-Free Fiberglass Pool
- Fiberglass pools are easy to maintain—but not maintenance-free
- Use soft tools to clean and avoid damaging the gelcoat
- Maintain ideal water chemistry to prevent stains and scale
- Clean weekly: skim, vacuum, and brush gently
- Prevent the waterline ring with routine wiping and swimmer rinses
- Use vitamin C or ascorbic acid to remove stains safely
- Protect the gelcoat with proper chemistry and non-abrasive care
- Close and open your pool the right way to avoid long-term issues
- Call a pro when in doubt—especially for persistent stains or surface concerns
With a little attention and the right habits, your fiberglass pool will stay clean, beautiful, and ready for cannonballs all season long.
FAQs
Q. What is the best pool cleaner for a fiberglass pool?
A. The best cleaner is one that’s non-abrasive and safe for fiberglass surfaces. Look for gel-based or liquid pool cleaners specifically labeled for fiberglass. Use them with a soft sponge or microfiber cloth to avoid scratching the gelcoat. For regular maintenance, a robotic pool vacuum is a great investment—it’s gentle, efficient, and keeps your pool floor and walls clean with minimal effort.
Need help choosing the right cleaner? Sutton Pools offers free guidance and product recommendations tailored to your pool’s needs.
Q. Can you pressure wash a fiberglass pool?
A. No, pressure washing is not recommended for fiberglass pools. The high pressure can damage the gelcoat and create tiny cracks or rough patches where algae and stains can form. Instead, use gentle brushing with a soft-bristled brush and a fiberglass-safe cleaner.
If your pool surface looks dull or stained, Sutton Pools can restore it safely with professional cleaning and gelcoat inspection. Contact us for a free consultation.
Q. How to rejuvenate a fiberglass pool?
A. To rejuvenate your fiberglass pool:
- Deep clean the surface using safe, non-abrasive products
- Balance your water chemistry (chlorine, pH, alkalinity, and calcium levels)
- Spot treat stains with a vitamin C tablet or magic eraser
- Polish or refinish the gelcoat, if it looks dull or worn
A full rejuvenation may include recoating the gel surface or even updating your pool features. Sutton Pools can inspect your pool, recommend upgrades, and give it new life—get in touch for your free quote!
Q. What maintenance does a fiberglass pool need?
A. Fiberglass pools are known for being low-maintenance, but regular care keeps them looking great. Here’s what you need to do:
- Skim debris from the surface several times a week
- Brush the walls and floor weekly with a soft brush
- Vacuum with a manual or robotic cleaner
- Test and balance water chemistry 1–2 times per week
- Wipe the waterline weekly
- Inspect equipment and filters regularly
For easy, expert maintenance help in Clarksville, TN, Sutton Pools offers service packages and seasonal checkups—plus advice on DIY care. Contact us for a free consultation and quote!
