my 10g tank just finished cycling 2-3 days ago the ammonia and nitrites fell to zero after about 2 months of waiting. I had 3 small guppys in there about 2 weeks ago and they are happy and fine especially since the cycling has been finished. After my cycling finished i did a 30% water change and went to store and bought 3 platys i floated them in bag while adding some tank water slowly then introduced them to the tank(2 males 1 female). Next morning i found the female dead and stuck to filter. Couple hours later one of the males was swimming into the current of the filter and then getting blown all over and running into things and then i found him stuck to the filter dead. the other male has been sitting at top left rear corner of tank and still sits there to this day. API test results are 0 ammonia and 0 nitrites PH is around a 7.0 and nitrates are around 10-20 ppm(color on my kit hard to tell). Maybe the platys were just so stressed from going into a new tank? or maybe the pet store i went to sells bad fish hmm... i have no clue why this would happen. My filter isnt even strong filter its the cheapo walmart 10g kit filter. Why did this happen??? someone told me maybe the platys need more oxygen in the water? should i buy a air stone and pump??? are platys slow swimmers that need a sponge covering on the end of filter so they dont get sucked into it?? another thing i just put some driftwood in that ive been soaking for about a month while testing ph of soak water the wood didnt affect it so i added it. the driftwood shouldnt cause my fish to die should it ??