Two of our 5 platys [two of the three exhibiting illnesses] died yesterday. The third one won't probably last the weekend. We did everything in the book, changed water, cleaned tank, fed fish less, gave salt baths and used medications the internet suggested we do. Alas.
So, I was wondering:
1. Can certain types of platys be weaker in constitution than others? Two of the three that died are called, I believe, "Spotted". They are shorter in size, and given to seeking dark places, than the "Hallie/Halley" type that seem to be thriving. They were both also male. We believe the 5th fish that we introduced into the tank [a white/yellow? mickey mouse platy female] may have brought the disease, as things were not looking half as bad before she arrived. [We are also exploring ways on how to harden our water, per your suggestions]
2. Is it possible for illnesses to be passed into fishes of the same breed, and not to others?
3. Is insomnia a thing in fish? One of the two resilient species in our tank appears to always be up and swimming around every time we passed by the tank, even after the light is out. I tried wrapping the aquarium with a dark cloth, making sure all air entryways were open, a few days ago and she appeared fast asleep when I took it off in the morning. [She is usually still swimming around, despite no light and other fish being asleep, in the morning]
And is there anything we can do about it?
4. Is it generally unwise to keep an aquarium in the kitchen? We live on the 3rd floor of a wobbly apartment that threatens all things not nailed-down every time someone run up the stairs. And the kitchen island is the only thing that can support a 10 gallon tank in the whole place. Now, we are not cooking people. Twice a week, save for the occasional steaming of vegetables and popping [?] of pop-corns, is all we do. But I have been wondering if the smoke/steam/smell won't affect the fish badly, and contribute to a short life span.
4. If we decided not to get anymore fish, will the two surviving female platys be content?
Thank you for all your help on this journey. Please find here below a photo taken about a week ago. The two swimming in the picture are alive and well, the three fish lying at bottom of tank --- not so much. [Thought visual works better]