Can this sealant be applied to a pond or aquarium while it’s filled with water, or must the surface be dry first?

It can be applied directly to wet or submerged areas. This underwater sealant fully cures in 24 hours and becomes a pond sealant fish safe once dry, making it ideal for aquariums, koi ponds, fountains, and other aquatic environments.

Will the sealant bond effectively to a wide range of surfaces like wood, metal, plastic, stone, and glass?

Yes, this hybrid polymer sealant offers strong, flexible adhesion to glass, stone, plastic, and more. It also performs well as a glass sealant, ensuring waterproof protection and long-term durability on a variety of indoor and outdoor surfaces.

Once the sealant is fully cured, is it safe for all aquatic life, including koi fish, turtles, and amphibians?

Once cured, it’s completely non-toxic. It works as a koi pond sealer and pond sealer safe for fish, reptiles, and amphibians. Ideal for tanks, ponds, or habitats where the safety of aquatic animals and plants is critical and long-lasting.

Is this suitable for sealing bathrooms, kitchen sinks, or windows where strong waterproofing is essential?

Absolutely. It works as a window sealer and waterproof silicone for high-moisture areas like showers, tiles, sinks, and windows. It delivers long-lasting protection, prevents mold buildup, and provides a clean, nearly invisible finish.

Will this product stay flexible after curing, especially when exposed to outdoor temperatures and movement?

Yes, it remains permanently flexible after curing. This adhesive sealant resists cracking or shrinking, even in changing temperatures. Ideal as a floor sealant and for roofs, walls, garden features, and high-movement outdoor joints.

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MS300 Marine Grade Pond Sealant, Black, 300ml | Window Sealer, use for Leaks, MS Polymer Adhesive, 4x Stronger than Aquarium Silicone Caulking, Marine Adhesive, Pond Liner

Product ID: 532406096

Details

Brand
MyPond
Item dimensions L x W x H
23 x 5 x 5
Item weight
295 Grams
Material
Silyl Polymer
Style
Compact

🌊Marine grade waterproof sealant

💪4x stronger than silicone

⏱️Cures underwater in 24h

R1023

Duties & taxes included

In stock

Sold byAmazon South AfricaDelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

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Description

Seal it like a pro, waterproof your world! 🌊

FISH SAFE FORMULA 🐟 - Protects aquatic life with a non-toxic sealant ideal for koi ponds, aquariums, and fountains.
VERSATILE BONDING 🌐 - Bonds seamlessly to concrete, wood, glass, metal, plastic, and more for all your sealing needs.
UNMATCHED STRENGTH 💪 - 4 times stronger than traditional silicone for durable, long-lasting pond repairs.
RAPID UNDERWATER CURE ⏱️ - Sets fully underwater within 24 hours, accelerating your DIY projects without downtime.
ALL WEATHER DURABILITY 🌧️ - Marine-grade waterproof sealant designed to withstand harsh outdoor conditions year-round.

The MyPond MS300 Marine Grade Pond Sealant is a 300ml black hybrid polymer adhesive designed for professional-grade pond and aquarium repairs. It offers 4x the strength of standard silicone, cures underwater in just 24 hours, and bonds to a wide range of materials including concrete, glass, and metal. Its fish-safe, marine-grade formula ensures durable, waterproof sealing that protects aquatic life while delivering fast, reliable results for all your water feature maintenance.

Specifications

ASIN	B0C2VBJ2BL
Best Sellers Rank	975 in Garden ( See Top 100 in Garden ) 10 in Pond Care & Water Treatment
Brand	MyPond
Compatible Material	Concrete, Stone, Wood, Glass, Metal, Rubber, Plastic, Fiberglass, Acrylic, Glass Reinforced Plastic, Porcelain, Vinyl, StoneConcrete, Stone, Wood, Glass, Metal, Rubber, Plastic, Fiberglass, Acrylic, Glass Reinforced Plastic, Porcelain, Vinyl, Stone
Country Of Origin	United Kingdom
Customer Reviews	4.6 4.6 out of 5 stars (384)
Item Dimensions	23 x 5 x 5 centimetres
Item Form	Liquid
Item Weight	295 Grams
Manufacturer	MyPond
Manufacturer Part Number	Ms-300
Material	Silyl Polyether Polymer
Number of Items	1
Number of Packs	1
Style Name	Compact
Surface Recommendation	Window
Unit Count	300.0 millilitre
Water Resistance Level	Waterproof

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