problem with my live bearing fish

[fatfei]

Hi,

I have had a two of guppies die over the space of 3 weeks. They just disappeared. I had 12 mollies (most of which babies and 12 neon tetra and 2 shrimp and snails. My big Molly was hanging at the bottom when I left Sunday which seemed strange for it and when I come back 4 days later (automated accurate fish feeder) I had lost most of the adult mollies and 2 babies. I have noe lost another adult Molly and the last seems to be going. All 12 neon tetra and japanese shrimp are not affected. The mollies are generally laying at the bottom although I've seen them hovering at the top too. They are shying away and I have seen one of them rubbing on the sand and another keep flicking himself. The fin on the black Molly is a little faded at the tip but might be his natural look. One of the mollies had cloudy eyes and another had what I can only describe as bits of lose sling on its tail. A baby Molly just wiggles at the bottom of the tank. I am currently treating with myxazin on the advice of my local shop. Any other ideas?

Cheers. P.s water ammonia and nitrite is 0 and nitrate is 30.

 

[fort384]

Tank size? Temperature? pH? Maintenance schedule?

 

[fatfei]

150 ltr, ph of 8 and 15% water change weekly as always since the tank was setup over a year ago.

 

[StuH]

What kind of shrimp, are they ghost shrimp/ freshwater prawns these grow quiet large I had two that where huge and used to grab my fish out of the water and kill them. If ur fish are hanging near the bottom it could be fair game to them.

 

[fatfei]

What kind of shrimp, are they ghost shrimp/ freshwater prawns these grow quiet large I had two that where huge and used to grab my fish out of the water and kill them. If ur fish are hanging near the bottom it could be fair game to them.

These are japonico shrimp. They are harmless, there is defiantly a disease in the tank, my black molly has a cloudy eye and tips of his fins are faded in colour. Although i am hoping it is starting to get better since the bacterial treatment i have been putting in, it still sits at the bottom a lot and hides but does come up more now and eats too so my fingers are crossed. What ever it is whats wrong with the mollies and guppies it does not affect the neon tetra or shrimp they are all as normal