Hi everyone,
I've been a long-time Aquarium Co-op fan, but this is my first time posting on the forum. About 6 weeks ago we got 9 endler guppies from a generally very good LFS. There were 4 obvious females, 2 males, and one that has since matured and is now obviously a male. They had bred in the store and all seemed energetic and ate well, so I assumed they didn't have any disease and didn't quarantine. A week ago one of the females gave birth and we have 3 growing fry from her now, but she looked stressed the next day (breathing heavily and hiding) and died two days later. Today, which is about a week after the first female showed signs of stress, one of the males died. The fish all seem lethargic and the ones that have died have been breathing heavily in the final stages before death. In appearance, the fish all seem healthy. I did also see one of the fry flash on a rock once, but it seems like an external parasite/infection is unlikely since the fish all look fine. Maybe he flashed due to ammonia irritation.
Here is a video of the fish soon after we brought them home. I've also added pictures below of a group shot, the male who died today, and a (admittedly bad) close up a surviving male and female together that the forum software seems to have flipped.
Water Parameters:
Temp: 80 F
Ammonia: maybe 0? I use the API test strips because I've had allergic reactions to the API liquid test kits for ammonia and nitrate. My ammonia strip was a bit green at the edges of the pad but mostly bright yellow (See the picture below) so maybe there is some ammonia in the water.
Nitrite: 0
Nitrate: 0
KH: 180 ppm
GH: 120 ppm
pH: 7.5
The tank is 12 gallons with a sponge filter, a dirted center island-scape where crypts and rotala are planted, and the water surface is covered in giant duckweed, so I hesitate to say that there is an ammonia issue, because duckweed has always kept my cherry shrimp tanks perfectly clean with the same sponge filter setup. The sponge filter has been established in a shrimp tank for over a year before I moved it to this setup.
To address this, so far I've add a 1.5 dose of Seachem Prime (38 drops) straight into the tank in case it's ammonia causing the issue. The tank has had 2 ~40% (5 gallon) water changes since it was set up, with one of them being about 10 days ago.
I live in Canada, so my access to medication is limited, but I do have copper drops for ich, "planaria zero," which I'm pretty sure is just a generic de-wormer, fenbendazole, the API salt med.
What do you think could be the issue here? We would love to fix this because the tank is at eye level for our two daughters and they love the fish and are excited to keep seeing the colony grow.
Thanks,
Reed