I have a 29 gallon tank and it has suddenly turned cloudy to the point where I can see anything! I have an autistic son and this morning he decided to drop a dill pickle in the aquarium. My wife got it out as soon as possible. I cleaned the tank yesterday including change the filter. The water was fine for a while after she got the pickle out. In a matter of 5 to 6 hours it changed. I have lost 3 fish already. Any suggestions