If I put these fish in will they get ick?

So as you may or may not know I have a 5.5 gallon planted aquarium with a Nerite snail 🐌. Two or three weeks ago I had fish in there but they all died of ick. Since then I have replaced at least 70% of the water. I am thinking of catching mosquito fish from the body of water behind where I live to see how they do. If they start showing signs of ick would it be wise to release them back?