Originally Posted by Richard Gb

There are some paint companies out there who claim that their paint/ varnish is "aquatic friendly" I always contact the manufacturer of the paint/ varnish which the customer wishes to use and ask first. The reason being is this-

Some ( and I stress some) paint/ varnish can not any be toxic to aquatic life if dropped/ dripped into a pond whilst wet, but can also be toxic for some time after it is dry. This happens because the rain/ garden sprinklers/ hose pipe soaks the paint and this then drops into the pond taking the toxins with it!!!

Contact the manufacturer of the product you wish to use (their contact details will be on the can) and ask them. If they say it is safe ask for this either in writing, by e-mail (with a name) or by fax. This way your solicitor knows who to sue if things go wrong!!!
Sorry to put such a negative post up but as a professional pond builder I do not want to see the fish suffer and would rather give the correct advice than keep quiet!