Help! 2 died .. 1 not looking good :cry:

[jyjy]

I keep kois in a fibreglass pond. 'B' shaped 1.4 in length, 0.5m in depth. build-in filtration system. There were 4 kois (approx 60cm) and 4 other small ones (approx 15cm) and a small catfish

It happened very fast. i noticed that the fish were swimming to the surface alot, staying stationary in a vertical position for a long period of time. Thinking that it's probably the lack of oxygen in the pond, i changed half the water hoping to improve the situation. Apparently, it didn't help much and the fish continued swimming to the surface. After about 5 days, which is today, a fish turned up dead.. about 12 hrs later.. another died.. both were the larger kois
Presently, one of the large koi is still adopting the vertical postion close to the surface. i hope it wouldn't die.. Help!!
Is it the water?

Thanks, really

 

[Menagerie]

[center:8376e9454e] Welcome to AA, jyjy! [/center:8376e9454e]

How much surface agitation do you have in the pond? What are your water parameters (ammonia, nitrite, nitrate)?

 

[Devilishturtles]

I'm gonna take a guess and ask what the temp of the water is? Since Koi are coldwater fish, perhaps your water is heating up too much...kind of a longshot, but something to check.

Along with your other parameters, should help to identify the potential problem.

HTH

 

[jyjy]

hmm.. i don't know about the ammonia/nitrite/nitrate levels. Yes, i read about the article about these factors. How do i check them? How do i rectify such a problem?

Water temperature? Since i am in singapore.. i think it's about 25 degree celsius. Is it too warm? What can i do?

thanks for the help

 

[Menagerie]

You can buy water test kits for ammonia, nitrite and nitrate at a LFS. You will want the liquid tests, not the strips.