Question 1

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

Accepted Answer

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.

Question 2

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

Accepted Answer

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.

Question 3

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

Accepted Answer

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.

Question 4

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

Accepted Answer

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.

Question 5

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

Accepted Answer

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.

ASIN	B0C2VBJ2BL
Best Sellers Rank	2,151 in Garden ( See Top 100 in Garden ) 29 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	4.5 4.5 out of 5 stars (373)
Item Form	Liquid
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

MS300 Marine Grade Pond Sealant, Black, 300ml

Details

Details

Description

Specifications

Common Questions