Question
I put some wd40 on a pump and then stuck it in my 150 gallon pond
I immediately saw the oil coming out and grabbed it out. Will this hurt my fish?

Answer
Dear Myron,

Thank you for your mail.
Unfortunately oil is indeed harmful for all waterannimals.
Probably however you did not use to many wd40 on it and is the damage of that range that it is possible to remove.
My advice is to add a pump and skim off the surface oil if possible and this as soon as possible.
This to ensure no oil will get on the fish and in the gills. In the gills and intestins it can harm  the fish.
So if you act immediately the harm can be minimal.

good luck!

Kind regards,
Raf