Tank Full Of Problems

[ReiRei]

Hey folks
 
Am posting for help with my 90litre community tank. I've had a burst of strange occurances in the last week or so.
Firstly, I noticed one of my black lyre tail mollys had a dull grey patch on her, in a circle shape. It's flat, and sometimes there are two - I'll upload a picture later, but any ideas? Definetly not white spot. Or a lump.
 
Secondly, I had one of my white male mollies randomly die on me. It spent a couple of hours sitting around the bottom with no energy to swim, and passed away in the night. On inspection of the body afterwards, I could see no signs of wounds, rot, or anything like that.
 
Third, One of my black lyre tail mollies (not the one above) seems to be terribly skinny. She comes to the top in the morning for food, yet seems to be unable to find it - almost as if she's blind to it?
 
Lastly, I woke up this morning to my female swordtail unable to swim down, and a large stomach. Seems to be swim bladder, but she's in a quite late stage of it - is this even possible in one night?
 
My tank currently has little lighting, and has been like that for 2 weeks - could this effect fish? Or just the plants?
I treated this morning with Internal Bacteria treatment for the swordtail, but as I can only treat one thing at once, I am worried.
There are numerous fry in the tank, all seem perfectly healthy.
 
Checked the water this morning, ammonia is at 0, (Nitrite to be added later, didn't have enough time, but no signs of fish gasping.)
All other fish seem to be fine for now.
 
Fish: 4 Mollies, 4 Swordtails, 2 BNPs, 1 Siamese Fighter female, 6 Platy, Various fry.
 
Unfortunatly, I have no free tank to quarantine any fish.
 
Sorry to ramble on D:
Any help is appreciated.

 

[Sophie]

How long has the tank been up and running for and also what did you do to cycle the tank? Did you pop fish straight in or did you had a bacteria or ammonia to cycle it.

If it's fully cycled there should be 0 ammonia and 0 nitrite. Need to check the nitrite and get back to us.

 

[ReiRei]

Tank has been set up since beginning of april, used a filter start when I first added water. Fish were put in 2 weeks later.
 
I'd imagine the nitrite is at 0, but of course I'll need to check that - am at college currently.

 

[mrhidley]

I've had problems in the past keeping mollies and having them die for no apparent reason, so I've stopped keeping them. From what i have read it's to do with Mollies preferring slightly brackish conditions, without it, their immune system isn't very effective.

 

[coolie]

Just be weary that circle shapes can be TB and humans can catch it from fish. Not trying to scare you or anything and can't say as we don't have pictures or anything to go on but you need to get to the bottom of it.

 

[ReiRei]

Update:
Nitrite is at 0, and the swordtail who developed over-night swim bladder has passed away.
 
Looking for some speedy advice D;
 
The patches on the black molly are grey and round, both on her back.
Also, the anorexic looking molly is gasping for air at the surface in the mornings when it's feeding time.
 
If it was TB, wouldn't the fry be dying off quickly?

 

[ReiRei]

Another black molly female is beginning to act lethargic, as is the white female molly left.

 

[zupeer]

Well this might not be much help, but I experienced something similar with my corys a couple months ago. They started dying off one by one, each acting lethargic one week after another and then dying with no signs of illness. My water parameters were good too so I never found the cause.... I pretty much gave up on raising corys all together. All I can say is check Ammonia and Nitrate lvls, and maybe do a 30% water change and see if that helps. It's possible they have some internal parasite or a disease that's not noticeable until they die... That's how my corys all died /: No signs of illness until the day they went lethargic or died.
Hope I didn't upset you, fish can take a turn for the worse overnight with no real explanation. Try water changes and checking your levels and maybe start feeding them foods soaked in some fresh garlic to boost their immune system, or give them chopped up green peas. Maybe that'll help them recover...
Good luck, I hope you your fish get better.

 

[ReiRei]

Only the white molly died without any signs of illness, ammonia and nitrite levels are posted above.
The other fish are showing various illnesses

 

[DoubleDutch]

Mollys like it hot and salty / brackish. If nog they can get some osmotic problems. How often do you do waterchanges ?

Suddenly dying Corydoras can be due to chlorine in water.

 

[ReiRei]

I do water changes on the 90litre every 6 days. Temp is at 80

 

[ReiRei]

Male black molly is now sitting on the gravel and not moving much.

 

[coolie]

It might be worth introducing some salt for it's mild  anti bacterial properties, in view of the fact the mollies would like a little, although you'll need to check if the other fish can tollerate it with some of the other experts on here as I don't know all the fish in question.

 

[ReiRei]

Quick update - After more fish have died, I've been led to the conclusion of internal parasites. The recent deaths have been fish getting incredibly thin, and pale stringy poo before dying.
I am currently feeding them flake soaked in garlic, and meds are on the way.
Fingers crossed!

 

[ReiRei]

Lost another molly yesterday. Hadn't been dead for long, but immediatly had turned white-ish? (Molly was black.) Although I noticed the plecs trying to suck it to death, could that have caused it?
Also - Does my female betta look a tad skinny? Hoping she survives this parasite phase.