Sick Rocket Pencils - please help!

[ashbaxter]

Hi guys,

Ive had six rocket pencils who have been living peacefully in my 100 litre community tank for over a year now. But in the last week i have had 3 die :( they werent acting themselves, had gone from all hanging out mid tank to mostly being at the top and more so floating around.

The only change to the tank in the last month was the addition of 6 clown kilifish. Ive moved the remaining three into a nursery net but have not moved them to another tank for fear they may be sick,

Does anyone have any ideas? please help!!!

[MuckyFish]

Did you quarantine the killifish first?
What are your water parameters?
What is your total stock in that tank?
What are your water change, feeding regimens?

We don't have much to go on without some more details like the questions above. Anything else you could tell us would help probably.
I could hazard half a dozen guesses but that probably doesn't help at this point.
A picture of or the latin name of the rocket pencil fish might help. Want to make sure I am not confusing the fish you actually have with something I think you have.

[ashbaxter]

Thanks Muckyfish!

no i dont have a quarantine tank so they went through my nursery net and then into the tank.

in this tank there are-

2x blue ram
5x peppered corrys
1x bristlenose
5x cherry barbs
10x mosquito rasbora
6x clown kilifish

I change 30 litres out each week and feed daily a combo of sinking pellets and flakes with blood worms every few days