Help please!!!

[Josh Giro]

I came home from work today to feed my 4 fish (had 2 platys and 2 guppies, all male) and one of my platys was dead! Last night I added 3 Neocaridina shrimp and a plant. I tested my water last night: ammonia 0, nitrite 0, and nitrate really low, and then I added half a cap of Prime Seachem in case of anything. I just tested my water again, and the tests showed up the same and my water has been at 79°F steadily. I got these 4 fish a little over a month ago… They all seem to have lots of energy and were eating well. I feed them a tiny bit of Spirulina flakes once per day around the same time and have my light on a timer for 9 hours a day.

I’m just so flustered about why this happened?!? Is it because I added a plant and shrimp? Is it because I added some Prime? Please someone try to make sense of this for me

Also, I changed my background to a black background last night, but I don’t think that is the reason.

Any ideas/suggestions on what I should do now & should have done are appreciated! I can also take a picture of “Sunny” if needed, but would rather not. Thank you!

Edited August 15 by Josh Giro

[Whitecloud09]

I would suggest adding this to the “disease” forum on the forums page, @Josh Giro. As for help, @Colu might have an answer. Sorry about this!

[Colu]

What your KH and GH and pH as low KH can cause a lot of health issues with platys  any rapid breathing hanging out near the surface lethargy flashing any redness to the body of the one that died @Josh Giro

Edited August 16 by Colu