Dead Fish

[leenda]

I have a 4000 gal pond with 2 waterfalls installed a year ago. There were 18 koi until yesterday. One died then another died today. I took one of the live ones to the koi store to test for parasites and there were none so he didn't have any advice. Should I treat the water with salt? Why would they start dying now? I live in Texas and we've had a mild winter and the water was 64 degrees today. (If this information even helps.) I would appreciate any advice before I lose any more. Thanks.

[GregBickal]

Do you have city water, are you using declorinator? If the fish were not showing any visible signs, that might be the first place I would look. Test you water for Ammonia, Nitrite, PH. We need more to go on to make a diagnosis.

[leenda]

Are you the Greg that has June's fish from Waverly? If so, these are related to them.
Anyway. Yes, we have city water but I haven't added any lately. So, I should take a sample somewhere before I do a salt treatment?

[Terri]

Hello leenda,

Although the one fish you too to the koi place may not have shown parasites,... that doesn't tell you much as that one fish could be fine and dandy while a few other's might have a problem...

As Greg mentions, we really don't have much to go on. At the koi place do they sell water test kits? The master kits come with everything you need for testing your own water - Ammonia, Nitrite, Nitrate, and pH, as well as KH and GH (carbonate and general hardnes). If this place does not sell kits they should be able to test your pond water for you, if so make sure they write down and give you the values for each of the above mentioned tests.

Was there any outward signs on the fish when found dead? Sores?

Have the fish been acting 'odd' like flicking themselves on objects in the pond? Hanging at the surface near water returns? Anything you can think of?

A discription of your pond set up in more detail might help as well... like do you keep plants? Is there gravel/rock layering the pond bottom/shelves? What is your maintenance schedule like?

18 fish, all koi? What ages? Size? How long have you had them? Any new additions in the last few weeks?

Please do not add any salt until we can figure out what's up... there are some medications that can't be used with salt levels above 0.1%, and there are health issues that salt can not help.

sorry for all the ?'s...

[leenda]

No noticable sores. I did notice they were near the surface under the waterfall. There are 5 water lilies and 3 other shelf plants that are just coming back after winter. 18 koi - almost 2 years old about 10-12". I put in 2 banded shark last summer and just saw them today for the first time since they were added. And no other additions since summer. We recently had about 4" of rain. Thanks for your help, Detective!

[Jackie Ramo]

4" of rain could be a problem. Terri is right, please get the water test kits as soon as possible or have the water tested, marking down the numbers. Its ok is not good enough in these circumstances. Also what is good for a tropical fish can be deadly to a koi so we really need to know the numbers.

How are the fish acting now?

[leenda]

The others seem fine for now - not at the surface - just suspended midpond. I'll get a kit tomorrow. Is it difficult for a beginner to do the testing?

[leenda]

Oh...why might the 4" of rain be a problem?

[Ian]

How often do you do water exchange? Any rubbish on the bottom?

[leenda]

I add water as needed but am not sure what you mean by exchange. There are a few leaves on the bottom and some fluffy-like algae stuff. .(Don't know the technical name.)But I can easily see the stones and the water is very clear.

[Ian]

Oh It's not hard to use test kits :wink:

4" of rain can change the chemistry of the water.....thats why the test numbers you get from your pond water can lead us to or just rule out possibilities.

[Ian]

O.K getting a good idea what is up without a test kit :grin:

Because your pond is a closed system as water does not flow in and out it is essential to remove 10% to 20% of the water volume at least once a week. Toxins and bacteria, hormones and other nasties build up and have to be removed. The only way to do this is by draining water out and fresh water in..Dechlor if city supplied. Best if you remove waste while removing water at these changes.

Jackie is our resident pro on rock bottom maintenance. I need a nap and a pillow....

[Jackie Ramo]

Jackie is our resident pro on rock bottom maintenance. I need a nap and a pillow....


.... does your wife know you use my lap for a nap???? !rofl

[Terri]

.....But I can easily see the stones and the water is very clear. Clear water is not necessarily 'healthy' water for fish.

Thank you leenda for doing your best to provide us with more information... being in the pond + fish keeping hobby does require a bit of detective work now and then :wink: And usually the first step is testing the water for the things mentioned already. Ian's right, testing is very easy, each test kit comes with an instruction booklet which may also tell you 'why' you are testing for this or that... very good investment.

While we're waiting on the pond water chemistry test results.... I thought you might like to do a bit of reading. Tom Holder wrote a very good article Understanding Pathogenic Bacteria (http://www.koicarekennel.com/pathogen.html) Basically he describes bacteria counts in water and the effects on fish.. but this crosses over to other things as well. Koi Keeping, koi health & koi ponds (http://www.fishdoc.co.uk/koi/koiover.htm) and Fish health and water quality (http://www.fishdoc.co.uk/water/waterhome.htm) These last two will explain why water exhange(or water changes) are necessary for any pond housing fish, as fish are also somewhat 'open systems' and depend on the quality of their environment to maintain their health.

[Merlin]

Hi leenda , lots of good advice there but what would help more is some info on your pond, size depth, what filter you are using etc. The more info you can give, the easier it will be to help find the cause of why you are losing fish. From what you have posted my bet is that it is a water based problem, so the sooner you can check that out and pass on the readings, the quicker the experts on here can solve the problem.

The water test kist are easy to use, boy if I can use them then they must be easy :lol: . What ever you do , do not panic,,,,, thats my job :)

[leenda]

Just got back from having the water tested:
Ph 8.0
Ammonia 0
Nitrite 0

The people at the koi place were stumped as to why the fish may have died. So far today, everyone's swimming upright.
I appreciate all the help...

[Terri]

No noticable sores. I did notice they were near the surface under the waterfall... 18 koi - almost 2 years old about 10-12".... And no other additions since summer. We recently had about 4" of rain.Tests look fine, '0' for Amm and Nitrite are very good. 8.0pH is good, do you happen to have a previous record of what the pH before now?

Mystery? Maybe not....? Rain, helpful yet sometimes problematic in the same instance. Heavy rain fall can cause oxygen levels in the pond to flux, the first few inches(foot or so) can be very low while the under layers of water are fine... even with waterfalls and returns circulating water it's not fast enough,...temperature at the surface is also fluctuating, warmer or cooler, impurities/gases picked up in the atmosphere by the rain drops could contribute... there are cases where fish coming to the surface during a long heavy rain fall can be adversely effected and sometimes lead to premature death... It's like getting hit in the head with a baseball bat... sometimes you recover sometimes you do not.

Just thinking out loud, whether this happened in your case leenda, don't know for sure.

Regular water changes are an important part of fish keeping, topping up with a hose does not count - all that is happening is dilution of the toxins and waste build up... water evaporates but these things do not, minerals and such deplete but never fully resorted for balance. It's possible that with the rain fall and long time between water addition/exchange that the chemistry was there to do harm to the fish... survial of the fittest some would say. Again, just hypothesising as I do not know enough about what you have or have not done when it comes to pond maintenance.

Sorry, no straight answers.