Strange Tank Behavior (Looking For Feedback/diagnosis)

[Klonoa50]

Hey all!
 
Been a while since I've posted on here.  Had computer issues, and once I got the computer up and running again and forgot about this site until (of course) my fish started acting weird.
 
I have a 36 gallon bowfront aquarium (it's been cycled for about 5-6 months now) that's stocked with the following:
2 female platies (hightail and "normal") newest additions, about 3 weeks in the tank now.
1 Lyretail molly and 1 balloon molly
5 Julii Cories
6 Cherry Barbs
1 Pearl Gourami
 
Temperature: 78 degrees F
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: 20ish ppm
 
Food:
TetraColor Tropical fish flakes and Aqueon shirmp pellets for the corries (though everyone else seems to love 'em too).
 
Now for the strangeness.
 
About two weeks ago I noticed a single white fleck on the hightail platty's back fin (she has a black tail, so was easy to spot).  It looked exactly like ich, and she had been fairly stressed (the pearl gourami was chasing her whenever she came near the top of the tank and she was still new-ish to the tank), so I researched salt and corydoras, and determined that it *should* be ok, as long as I added it in slowly.  The next day however I saw no signs of ich, and everyone was acting healthy, so I decided to let things go, but started doing daily 15%-ish (5 gallon) water changes.
 
About a week ago I noticed my largest female cherry was acting strange.  She was hiding from the rest of the barbs in a corner and flashing on the rocks.  Later that night she tried to jump the tank once or twice.  When I did the water change that night I added a single tablespoon of aquarium salt to the 5 gallon pour-in (after stirring it in throughly) and watched the cories like a hawk.  They all seemed fine.  Went to bed and the next morning I noticed one had red gills, but the rest seemed fine.  I did a water change, didn't add salt, and started researching meds.  I quickly learned they're mostly formaldehyde and copper-based, which scared me considerably (seems like adding those would be terrible for the tank).  
 
The cherry barb since has seemed much better.  She occasionally flashes (and has what looks to be scar tissue on one side of her, which is gradually fading away), but otherwise has acted normal.  The cory with the red gills still h as red gills that seem to very slowly be fading back to normal and otherwise acts normal (though a bit more lethargic then the others).  I also noticed it had a torn fin, so I think it may be more coincidence and bullying that caused the issue, though I never saw it attacked.
 
Finally we get to the lyretail.  About 3 days ago I saw a very slight black stripe across his back (gold and black normally) when he was swimming at an obscure light angle.  I dismissed it as something I had never seen before.  I still only see it if looking and at the right angle.  Today however he has begun chasiong his tail.  It appears to happen only when he is chased by another fish (and when I fed him).  He'll spin after his tale ridiculously fast for a second or two, then continue on as if nothing ever happened.  It's the only symptom I see, otherwise he's behaving perfectly normal.  I did some research and the only thing that sounds vaguely similar to it is Whirling Disease, but it seems I'd have to have really bad luck to get that (sounds like its very rare) and from what I could tell it seemed to have no triggers (whereas he only seems to do it when "excited").
 
Only other thing of note is the tank overall seems to be a tad more aggressive on the whole lately.  The cherries seem to be picking on the lyretail molly more then normal (never noticed it before), and the gourami is more actively chasing the platty.
 
Thanks for reading all this (sorry for the page dump), and thanks for the help, in advance!  

 

[RRaquariums]

Ok so this is just from what I can tell by your story but hers my input.
The first fish that got what you think was ich probably got a very small amount dew to the stress of being chased then you added salt which is not very good for the Cory's and it sounds like one of them had an adverse reaction to it which made him a slow target and I'm sure fish being fish he got picked on which is why if I'm right he may have got bitten or hurt on his tail and even though it's healing it may still hurt him once in a while so he thinks another fish is attacking him and swings around to defend himself but obviously no one is there so he stops.
This is all just my opinion and I may be totally off base but that's my best gauss.
My suggestion to you is find a new home for the pearl gourami that tank is a bit small for him and they are kinda a bully so he will make more problems for your smaller fish

 

[Klonoa50]

Thanks for the prompt reply RR!
 
You may be right on the Pearl Gourami,, I'm not sure.  I did a lot of research on proper size and temperament going into getting him, and everything pointed to him being right for the tank.  That being said he's the fish I'm most tentative about having in the tank (due to both size and him being the only fish that shows any aggression), so I'll look into that more.
 
Unfortunately the Cory is not the one exhibiting the spinning behavior (or else I'd probably buy that theory, since it makes more sense to me then a really rare disease hitting my tank)... it's the Lyretail molly, and it's not just a single quick whirl around and stop.  It'll manage to fit a good 5-10 "twirls" into 2-second window when it goes off.  It doesn't appear to be voluntary either... one minute he's perfectly normal, then "bump" and off he goes like some sort of demon-possessed toy.  
 
Thanks for the input!  I definitely agree the Cory's reaction was probably from the salt stress (I find it unlikely I didn't notice its ripped fin before then), which I guess means if I need to treat the tank I'll need to use a medication instead of salt, which kinda scares me a bit (yay copper and formaldehyde) but ce'st la vie.

 

[RRaquariums]

Ok well the same goes for the Lyretail molly probably just has a cut and it hurts sometimes. I've seen my platys do the same thing if they have a cut they will just spin really fast and go nuts but then all the sudden they stop and go back to doing there normal thing I can't explain why but that's all I can figure.

 

[bluesword23516]

The Molly might have "the shimmies". I have never had it but the reason it happens is that mollies prefer brackish water so it might be reacting to you water because it wasn't acclimateled slowly or can't handle the fresh water.

 

[Klonoa50]

Thanks again for the posts!
 
Well I certainly like that explanation more than the whole "incurable disease thing", especially since from what I've been reading I should also be seeing some sort of deformity and a lot less motor control then I am.  Will keep an eye on him, but that makes me at least cautiously optimistic.  I've also noticed since I fed him that he's been releasing air bubbles and "gulping" at the surface occasionally (which is new), which could mean swim bladder related issues, though never heard of those causing ridiculous spinning before.
 
I don't think it's the shimmies... My very first tank (before I understood anything about fish raising) was a pure molly tank with no salt, and a lot of 'em had that.  This behavior seems too sporadic and too extreme for that.  My understanding is that the shimmies tends to be a back and forth rocking motion when the fish is standing still. 

 

[Klonoa50]

Mornin' all!
 
Will keep this quick since I'm about to head out for work, but I euthanized this morning.    When I woke up he was whirling uncontrollably, and when he finally managed to stop about 10 minutes later, he was permanently stuck in an L-shape and no longer able to controller his flotation (stuck with the middle of his belly touching the surface).  His jaw appeared to be broken, and he kept trying to "spin" but couldn't.  I netted him and put him in in a small 1-gallon container I had made as an emergency treatment tank and watched him for another half hour with no improvement (he just lay at the surface, barely breathing and twitching uncontrollably).  After it became clear there would be no improvement I put him down using the clove-vodka method.

 

[Klonoa50]

Going to semi-hijack my own thread here, since I feel bad making two topics in 3 days...
 
1) What fish medications (if any) have you guys found safe to use?  The molly has passed on, and I'm not convinced the cherry barb's occasional flashing (and white scar-like patch) is a reason to medicate, but if it does come to that (or something else happens down the road), I realized I'd have no idea what to use.  All the meds I read about seem to fall one step short of killing the fish... I was wonderin gif there were any you guys had found to be both effective and not very stressful for 'em.  Up until now I woulda used salt for external-based stuff, but that one cory's seeming reaction to it has kinda scared me off it for 'em.
2) Do you guys know what might cause a cories gills to go "see-through"?  The one I mentioned earlier passed away today, and I can't tell yet, but I think another of my cories may have slightly transparent gills too.  He's acting perfectly normal, no lethargy at all, but thought I would ask just in case I'm missing something.  My internet research and personal experience seem to point to it only happening when they're stressed, but I didn't see stress in the poor lil' cory's case, or in what maybe the new case.
 
Thanks again for all the help and sorry if I'm asking dumb questions.