My Parkinsony are dying

[BenA]

Hello all.

I hope that one of you might be able to help.

2 – 2.5 months ago I bought 2 pairs of Melanotaenia Parkinsoni, 3 weeks ago the 2 males died with few days in between them, no external signs could be detected. I took it as bad luck, talked with the shop and bought another 3. Within 4 days one of them started showing signs of ‘something is not right’, it was at the top of the tank with its gill covers wide open, no other signs. I took it back to the shop, they suspected gill flukes and treated it, yet the fish died 3 days latter. They have examened the gills but the gills looked ok. I have consulted the shop and it was suggested to treat my tank for flukes, which I did. During this time (started 4 days ago) another Parkinsoni started to keep itself to itself and today we found it dead, so now I am left with 2 males and 2 females. I have many other Rainbows in the tank and none of them display any issues, also all the Parkinsoni I bought are old stock that the LFS have since December.

Today I tested the water and have carried a 50% water change. The parameters are:
NH3 – 0; N02 – 0; PH – 8; KH – 8/9; GH – 17; NO3 – 25; PO3/4 – 5; Temp – 25C/77F.
The tank is 400Ltr/106Gl and the fish are fed with frozen and dry food including Repashy Green.

Thank you.
 

[Beau Burkhalter]

What about oxygen? Adding med to the water will make it even harder for fish to get oxygen 

[BenA]

Thank you for coming back.

I believe that O2 is ok as there is an air stone running on top of the filter, also the tank is heavily planted. Other then that the dead fish appeared before I have added the medication. I also think that lack of oxygen would effect most/all fish in the same way. So, no, I don't think that this is the problem and I don't want to start treating without knowing what is the problem. If bad turns to worse and there won't be a good suggestion I will have to do the "Trio".