Is polyurethane safe for aquariums

Polyurethane can be safe for aquariums if it is fully cured and specifically formulated for aquatic use. Standard polyurethane paints and sealants may contain harmful chemicals that can leach into the water, potentially harming fish and other aquatic life. Always choose products labeled as aquarium-safe or suitable for use in water environments to ensure safety. Additionally, allow sufficient curing time before introducing any aquatic inhabitants.