In the past week and a half, I've lost four of my 8 sids. I'm a little baffled as to what's causing this. They are all juveniles of 1 to 1.5" in size. I bought 2 of them in January and 6 in early March. All were quarantined in a glass, bare bottom tank for 3 weeks before moving to their current home, a 20 gallon tank with sand bottom with lots of hiding spots. They have five praecox rainbows as tankmates.
The only signs of illness is one had a slightly swollen abdomen. I did a kitchen autoposy and couldn't find anything, although I don't have a microscope so it was pretty crude. All four fish were covered in fungus when found, which was within 6-12 hours of death. Tank mates were ignoring the deceased, and there is no physical damage on any of them.
My water is fairly hard (GH 15 degrees) with little buffering. Normally my kH is 0 degrees and I was finding my pH dropped more than I was comfortable (6.0 or slighly less), so two weeks ago I added some crushed coral to the filter. This brought my KH to 1 and pH to 7.3. Could this be a factor? Seems like a slight change to me, but I have removed half the crushed coral from the filter.
- Tank is a 20 gallon long that has been running for over a year
78 F
GH 15 degrees
KH 1
Nitrates between 10 and 20 ppm
No ammonia.
Thanks in advance,
CKfish