Question
My neighbor has been throwing cigarette butts in my new pond. I wont have fish in my pond until next spring. Will the cigarette butts kill my fish if they continue to do this?

Answer
Your question is a first for me!  I've heard most everything.

You should absolutely get those cigarettes out of the pond.  Not only is nicotine toxic at high enough levels but so are the literally 100 other carcinogens found in a cigarette.  If there were just a few cigarettes stewing in a large enough pond, that might not do too much harm but imagine if an unsuspecting fish tries to eat one!  If they don't get it stuck in their mouth and instead manage to eat it, they will die outright.  After you remove the cigarettes, put a mesh bag of fresh activated carbon in the filter and let that run for a week or so to remove any leftovers from the cigarettes.

I would hope you could convince your neighbor to have a little bit more consideration but I know how hard it can be to change someone.  Is there anyway you can fence off or protect the pond?

When I paid workers to build my pond, they were smoking.  I'm hypersensitive to it.  I didn't have enough strength to tell them not to do so so I just hid inside when I should have been outside watching what they were doing!  Not only did they leave cigarettes around to clean up but they made a lot of mistakes on the pond.

I would worry that your neighbor could throw other things in the pond such as beer or trash or even poisons.  People have been known to add bleach or soap to ponds to just be mean.  I hope things can be resolved.  Good luck!