Fish have amazingly sensitive chemical receptors, they will spit out any food that would be inherently dangerous. One little strawberry versus an entire tank is not really going to pollute it a whole lot, nor change the water chemistry in any noticeable way.
Here's what I personally do: I always cut a small section of all the fruits and vegetables that I buy and give a piece to the fish. The fish decide if they want it or not. I've found some very interesting ones over the years, like my tiger barbs really like orange slices. My fish like spinach but not Swiss chard. They don't like pears. I've never tried strawberries, though.
Like with a lot of things, just watch, and if they don't want it, then take it out. Don't let it sit in there for days on end. To me, it's as simple as that. The biggest thing in my opinion would be to make sure the strawberries got a good washing to make sure that not pesticides or fertilizers were on them.
Here's what I personally do: I always cut a small section of all the fruits and vegetables that I buy and give a piece to the fish. The fish decide if they want it or not. I've found some very interesting ones over the years, like my tiger barbs really like orange slices. My fish like spinach but not Swiss chard. They don't like pears. I've never tried strawberries, though.
Like with a lot of things, just watch, and if they don't want it, then take it out. Don't let it sit in there for days on end. To me, it's as simple as that. The biggest thing in my opinion would be to make sure the strawberries got a good washing to make sure that not pesticides or fertilizers were on them.