Losing sids-- ideas?

[CKfish]

Hi all,

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.

Any ideas? My next step will be to remove 100% of the crushed coral, but I'm still baffled as to why that would make so much of a difference.

Thanks in advance,

CKfish

[NancyD]

CKfish, I'm so sorry about your sids, I got mine about the same time as you. In the shop 2 or3 of 12 had round pink stomachs so I waited a month to buy & 1 was still skinny. I was concerned about internal parasites but afraid they'd be sensitive to meds. I was going to try levamisole but then there was a discussion of anti-parasite food. Cybermeez said she used to use pepso to clean out new fish. It's been discontinued recently but some stores still have it.(It's got antibacterials so I thought good for unknown) I gave for 3 days as per label & by the last day the sids seemed quite bummed out, hiding a lot, not eating as much & not their usual frisky selves. It took a water change & a few days for the to return to normal. I'm not sure it did anything or even if it was needed but maybe could help. Theres also an antiparastic water treatment with prazi?, metronidizole & ? but Joe Loach lost his sids using prazi,( lowered oxygen level he thought?) so you may want to add over time if you use it or similar. Seems like someone, Jim Powers?, had fish that decayed rapidly but I don't remember if he was able to figure out what was wrong. Sorry, not too helpful. Have you had the rainbows long? Are your sids eating? When in doubt change some water & I think I'd take out the coral & maybe do charcoal until you decide on a course of action. Wish I could offer good advice.
Nancy

[CKfish]

Nancy, thanks for the ideas. I'm reluctant to start medicating without a diagnosis. I've used levamisole and metronidizole before when I had clown loaches that were losing weight. These sids aren't looking skinny, they've just started dropping.

I got the rainbows from a friend, and have had them in this tank for about 8 months now. If there's any disease in this tank, it came in with the sids and has laid dormant for a while.

Someone's now convinced me to try a broad spectrum antibiotic, so we'll see how that goes. The "fungus" may actually be a bacteria like flexibacteria that's overwhelme the fish and then goes externa. Pretty frustrating experience, so far. I'll keep everyone posted.