13 of 15 Koi have died!

[dogslife]

I need help! :(

I constructed a 1,600 gal outdoor pond last winter with a skimmer, biofalls filter and added a pressure filter this past summer. Pond is lined with boulders up the sides, with a double waterfall. Looks great but has been a nightmare.

Algae has always been a problem, can not seem to get it under control, even now in January the pond sides and bottom are covered with algae. I have tried Green Clean & Algae Fix and all kinds of bacteria, nothing has helped.

I have purchased 15 koi over the past year and I only have 2 left at this time. The koi are approximately 12" long.

I check the chemicals weekly, Nitrates & Ammonia have always been around 0. My PH always seems high at 9 and no matter what I do never comes down. I have checked the oxygen level twice and that seems very low also.

Any ideas on what is causing the loss of fish? Could it be the ph or low oxygen, and how can I increase the oxygen level of the pond?

Sometimes it seems they get stuck between the boulders. I have found several passed away head first between the boulders, is that possible? I thought the boulders would supply a place for them to hide.

What about the algae? I realise this is alot of questions, but I just lost 2 koi this past week.

Thanks.
Dogslife

[Ian]

O.K first...algae is good for the system. A must for healthy koi to me a least. A new pond needs to develope a whole wack of different species of algae,bacteria and other micro life to function as a closed system. The first couple years the algae goes out of wack dependent on fish load:wink: It,s more than just ammonia,nitrites,nitrates,as there are many different ways a pond can dispose of these items. Our goal as koi keepers is to provide a healthy environment that estetics can interfer with such as rocks and bolders trapping debris that will rott and increase certain bacteria that does a fantastic job removing ammonia but will also eat holes in the sides of your fish. I believe that some pond filters available on the market encourage the wrong bacteria because of basic design and in doing so promotes an inefficant setup in the actual pond design.
Using algaecides can lead to fish loss! Whether it be the chemicals themselves or the die off of the algae itself. You have to think baby steps in ponding as things take time to mature and for every action there is a reaction and will be compounded in a small closed system. I like to promote just a handful of koi the first season or two so your pond can sufficantly handle the load placed on it and so you can easily compensate on any short comings. This also holds for the visual inspections needed to observe the health of the koi as it's easy to keep track of say 5 to 15. Would need more info and history to help you narrow down and determining the reason for your fish loss. You may have a parasite problem so info on eating, scratching did you buy the koi at one place one time? Many Questions to be asked before better answers can be given.

[luke frisbee]

I'd check for copper poisoning from one of the products you have trid to control the algae..
but Brother that is just a guess as you haven't told us near enough to have a proper idea of what is going on...
and only keep 5 koi less than a foot long in a pond that size...ONLY 5

[Jackie Ramo]

A double waterfall and still low in oxygen??? something is amiss in the pond for sure.

first we have more questions than answers.

Test the water and give exact numbers for ammonia, nitrItes, pH and kh. Pond temps will also help. Be sure water is a room temp when testing. The ammonia and nitrites must be 0 for healthy fish, no other number will do as both of these are poisonous to your fish.

Describe your maintanence schedule for the pond. water changes, filter cleaning etc.

What symptoms did the fish have before dying?

Do not add any more chemicals to the water unless it is a dechlorinator when you do a water change.

Welcome to the board. Hope we can help you with these problems.

[dogslife]

First I want to Thank everyone for thier quick replies. I was wondering which Koi forum to join, and I am impressed with the activity of this group.

In response to some of the questions above, I tested my water this past Tuesday.

Temp 44
PH 9
Ammonia 0
Nitrates 0
GH <20mg/L
KH 20mg/L
Oxygen 8mg

It seems to me that the GH is very low and the KH is very high, is that normal or is that tied to the high PH?

Thanks again.

[Jackie Ramo]

Do you mean NitrItes rather than NitrAtes, those darn vowels are a problem. I'd not worry about NitrAtes but NitrItes need to be zero

How are the fish doing?

Water test results seem fine to me.

[koicrazy]

Dogslife, Sorry to here about your trouble. I think the stuff used to control the algae could be the cause (like Luke said). I will not use any of that stuff to control algae about the only thing I use is koi clay. Also wonder about number of fish in pond. Usually it is 250 gallons per fish. Just remember a pond needs time to balance and if you keep dumping things in it that will keep changing the balance of the pond. The first 2 years are the worst. Marc

[luke frisbee]

Agreeing with Me? that doesn't happen to often...especially in public :wink:

Because of how the lack of symptoms and the condition and positions they were found, it seems as though a copper :-? cocktail :-? was the cause

[koicrazy]

Now Luke don't let this go to your head. This could change at any moment. :grin: Marc

[dogslife]

Thanks everyone.

Yea I did mean Nitrites. I did loose another fish yesterday. It seemed like he had an injury along the dorsal fin with a deep gash in the middle removing part of the fin and muscle. We have had a winter storm front move in and the water temperature has dropped to 40 overnight.

Now I am down to 1 fish. They seem to float around aimlessly prior to dying, with thier tail higher then thier body.

Any ideas?

[Jackie Ramo]

Head down tail up is classic sign of internal bacterial infection. The fish will need to be brought inside and warmed to survive. I believe antibiodic shots would be the best cure but there are some dips on the market. If the belly is reddish the infection may have gone septic.

What kind of preditors do you have there, the injury the fish died of seems most likely caused by a preditor.

[ozzyrockman]

Hello dogslife, I wanted to find out if you are doing your water tests at room temp of not. If not take a water sample in and leave it sit for about a half an hour before testing this will give you an accurate reading from the water samples. Are you on city water?

As suggested lower the fish load you have on your pond, keeping in mind that in western Washington we get our share of precipitation so water changes are almost pointless during fall and winter unless you have a covered or indoor pond because when in rains for say 20 days straight mother nature does a fine job of changing out our pond water for us. During the spring and summer make sure you are doing weakly water changes of 10% and one or two major water changes of 50% early fall mid spring. Also do not wash the filters in spring and summer with tap water, clean the media with pond water only.

The Ph is probably a result of the boulders in your pond and will not harm them however it sounds as if the gaps in the boulders are creating problems for you so remove them or fill them. Did the rock get washed prior to install?

If you are going to make any changes to the pond now would be the time. Last year I was feeding at the end of Feb however we had a very very mild winter and seems not be the case this year. I would suspect that it will be a normal year and we will probably be feeding in late March so if changes are made you have about a month to make changes in pond construction and this is an excellent place to start getting those ideas.

Allen