Dead Guppy

[Betta_Shark5678]

This morning when I was feeding my fish I noticed one of my guppies didn't swim up for food, after looking around the tank I saw him lying next to a fake plant, twisted in a weird way. I removed him immediately.

Tank size: 3.5 Gallons (temporary)
pH: 7.2-7.6
ammonia: Looks like higher than 0, but lower than .25ppm.
nitrite: 0
nitrate: Slightly orange, but not to 5.
kH: Unknown (unable to get the kH, gH test kits yet.)
gH: See above
tank temp: 77 degrees

Fish Symptoms (include full description including lesion, color, location, fish behavior): This fish had been swim vertically often. I posted a topic in the livebearer section about it a few weeks ago, and they said it may have been swim bladder disease. When I took him out of the tank I noticed that behind his gills was a brown color, other than that his colors were bright, and normal.

Volume and Frequency of water changes: about 1 gallon every week

Chemical Additives or Media in your tank: I'm not sure if I understand this question... Sorry, but could someone explain?

Tank inhabitants: 2 other guppies, and a male platy.

Recent additions to your tank (living or decoration): The platy is the most recent, but I added him a few weeks ago.

Exposure to chemicals: None.

Digital photo (include if possible):

 

[crazyforcordoras]

Chemical additives or media means things you add to your tank, carbon in your filter, algae removers,etc.

 

[Betta_Shark5678]

Okay, thank you. I haven't added anything like that, there is carbon in my filter cartridges though. I haven't changed the filter media though, and they've been in that tank almost a month.