>>Thanks for the quick response! I will definitely not be putting turtles in my fish pond now.

You're welcome. But ya know you could have a turtle pond instead of a fish pond. lol
No actually turtles can get sick and need a lot of vet care so it may be very costly to keep turtles especially if you've not kept them before.
Of course the way veterinary medicine is going these days, the same can be said for fish, they can get sick too and now more vets treat fish too.

Good luck with your pond!
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PHRatz