Hey Fish peeps
I've recently made the potential mistake of setting up a small 65 liter (17 gallons) aquarium for my aunt, stocked with 10 cardinal and 10 ember tetras (I know this may be slightly over stocked, she bought the fish without me). For the past week she's been having some die-off of the tetras. One or two a day and now shes down to five cardinals and 8 embers.
The tanks been running for a month and a bit now, cycled using existing media from one of my larger aquariums. I tested the water on Saturday and did a 25% water change after. I used the API master test kit except for GH/KH where I only had tetra test strips on hand. The test numbers were:
PH: 6.8ppm
Ammonia: 0ppm
Nitrite: 0ppm
Nitrate: 10ppm
KH: Between 4 and 8 (only had test strips to check)
GH: Between 4 and 8 (only had test strips to check)
Temp: 24 degrees Celsius (75.2 Fahrenheit)
I'm really sorry I don't have a picture to attach of the tank. But it has Fluval stratum substrate, multiple plants (Anubias, java fern, and crypts). There's also a piece of spider wood and dragon stone. The filters are an Aquaone HOB and a sponge filter.
Any ideas what could be the culprit of the dying fish?
Thanks All!!!!