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FlowBase™ – Waterproof Swim Underwear for Periods
●●○○○ | Moderate - Check out our absorbency guide here
Swim, float, dive, or lounge—FlowBase™ is your discreet, absorbent swim-safe underwear made to wear under your regular swimmers. Designed especially for teens, FlowBase™ is as comfy as your fave undies, only water-ready.
Perfect for school swimming, squad training, or any time they’re required to wear their usual bathers. With a high-leg cut and flat, seamless design, FlowBase™ sits smooth against the skin for a no-show effect under most styles.
Recycled Nylon
When your undies arrive, have her try them on over clean regular underwear before use to check the fit. Give them a wash before the first wear to activate the absorbency.
Then simply wear them like any other underwear. How long she wears them will depend on her flow. We recommend changing every 6-12 hours.
Step 1 Wash your Eco Period underwear before wearing / using them. This activates the EcoTech and primes it for use.
Step 2, After wearing, rinse in cold water until the blood/ fluids are mostly removed. You can do this in the shower to save water, but just do it before the water heats up past 30 degrees, as heat will set stains into the fabrics.
Step 3. Pop your undies into a delicates wash bag and into the washing machine on a cold wash. Use a liquid natural detergent.
No fabric softeners.
Step 4. Hang dry on the line outside. Line drying is best as it is kinder to the fabrics. Just don't leave them out on the line for days.
Eco Period underwear should NEVER:
Be cleansed with harsh detergents (these abrade and break down clothes which shortens their effectiveness and lifespan)
Be cleansed with fabric softeners (it's like fabric cholesterol and blocks the pathways in the fabric through which the liquid travels)
Be bleached (bleach kills everything, need we say more)
Be dry cleaned (putting the products into such a harsh environment with or without the added chemicals is bad)
Be washed in very hot water (heat breaks down the fibres and natural compounds that make these products so effective.
FIRST TIME WITH PERIOD SWIMWEAR?
Here's everything you need to know.
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Period swimwear uses three layers working together: a moisture-wicking lining against your skin, an absorbent core that locks in flow, and a water-repellent outer layer that keeps pool or sea water out. You swim like normal, the fabric does the rest.
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No. The outer layer is water-repellent, not absorbent, so it doesn't soak up water the way a regular pad would. Only your own flow gets absorbed into the core, so there's no bulk or swelling. Some water may get through at times, but it doesn't blow up like a nappy would, and your flow remains safely locked inside.
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On a light to medium flow day, our period swimwear is designed to be worn on its own. On a heavy flow day, we recommend pairing it with a tampon or cup as backup, the same way you'd double up with regular period underwear or just change more frequently (you can also give them a quick rinse out and keep wearing).
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Most of our period swimwear holds approx. 30ml. Absorbency varies slightly by style, so check the individual product page for the exact figure before choosing for a heavy flow day.
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Yes. The leak barrier keeps flow contained inside the garment, so nothing transfers into the water. Chlorinated pools and salt water are already inhospitable environments for bacteria, and our fabrics are designed to hold up to that exposure.
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Honestly, most girls forget they're wearing them within the first hour. They feel like normal underwear.
The main adjustment is trusting that they're working, which usually happens after the first successful wear. Start on a lighter day at home so she can build her confidence before wearing them to school.
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Yes. Every Eco Period product, including our swimwear range, is tested PFAS-free and free from harmful chemicals. Nothing nasty next to your skin, in the pool, or in the ocean.
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You can, with a backup or with more regular changes. Pair it with a tampon or cup the way you would with period underwear on a heavy day. Worn alone on a heavy flow, any absorbent garment will eventually reach capacity quicker, so backup protection gives you the coverage margin you need.
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No, as long as the fit and absorbency match your flow. Leaks happen when the gusset doesn't sit where your flow needs it, when the fit isn't right, or when a light-absorbency style is used on a heavier day, not because the garment has failed. Get the fit and absorbency right and it holds.
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Rinse in cold water straight after wearing, then machine wash cold on a gentle cycle. Skip the fabric softener, it breaks down the absorbent layers. Line dry rather than tumble dry.
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Snug around the leg openings is the key fit point. That's what stops water getting in and flow getting out. If the legs are loose, size down rather than sizing up.
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With the rinse-and-wash routine above, expect it to perform season after season. Skipping the rinse or using heat to dry is what shortens the life of any absorbent garment. The Racerback pro is the most durable as it is made of professional grade polyamide, which is a swim performance fabric that is chlorine resistant.
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Yes, it's built for movement, laps, surfing, paddle boarding and everything in between. Just make sure the leg fit is snug before you get in the water, since a loose fit is what lets water in during high-movement activity, not the fabric itself.
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Yes. It's a low-pressure way to feel prepared for swimming, whether her period has started or she just wants backup for the possibility. No tampons or cups required, just swimwear that works like the rest of her wardrobe.
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Snug at the leg openings, same rule as the adult range. Our teen swim bikinis and swimwear range is sized 8 to 16 and designed specifically for this age group, so the fit is proportioned for a teen body, not scaled down from an adult cut.