I lost 3 fish to my stupid error..please read!!

[Brutuscz]

My pond is 7,000gal and has been set up for 5 years. I have around 15 koi. My set up is a 4,000gal/hr submersible pump which is placed on the bottom of the pond. Well...this year I got sick of skimming by hand and figured I would make my own surface skimmer. I placed my submersible pump in this new homemade skimmer. It skimmed the water very well, the surface was like glass. About a month after I did this, I noticed the fish were not eating very well. Most of my big koi were looking pretty bad, I was unsure why? I tried different foods, and measured many things...ammonia,nitrite, alk, hardness,nitrate, ph even chlorine.....all good?!?!? I lost my Big Showa that I was planning on competing (The fish on the left in my signature), as well as 2 other fish. I found my oxygen test kit (which was hiding)...and Bingo!!! Normal should have been 8.3 for my water temperature....I measured a 6.0. I measured several times a day...never over 6. I installed a second 500gph pump at the bottom to move the water to the top. No change. I have now taken my 4,000gph pump out of the surface skimmer and placed it back to the bottom where it always was. I have a few fish that still look lousy...hanging near the waterfall, breathing heavy. Well, I anticipate the oxygen levels will return to normal, but I purchased a large air pump with a 6 tube manifold...just to be safe. I have been keeping fish for 26 years...and it just never occured to me the difference pump location can make with regard to oxygen content. It took one month to see such a large change. Its a learning process...but a crappy one. I hope people learn from my HUGE mistake!!! Thanks for reading.

[woodyaht]

Eeeeee-gads, sorry for your loss.
Tough way to learn
I was going to take some of my fish to a show this fall, but one of my favorites jumped last night, so probably won't show this year.

[bekko]

No way a D.O. of 6 will kill koi - 1 maybe. If they are that sensitive to a change in D.O. you must have something else going on. I think you need to keep looking - a gill parasite perhaps.

-steve hopkins

[markam]

Sorry to hear about your loses , you said you made your own skimmer ?? Is it poossible the materials you used were not fish safe ?? And whatever was not fish safe has now been diluted over time.

Mark.

[dick benbow]

I too, am sorry for your losses. And I think Steve is right on with his suspicions.

6 is strong enought not to cause issues as you discribe. There is spmething else going on there that is affecting their ability to breathe. carefully take a look at the gills with the survivors.


Get back to us, so we can help. There are several Professionals who monitor this board like Arthur that can guide you thru the correct steps to take.

[Brutuscz]

Well...the toll is now up to 4 fish, and number 5 is on the way. It has only been big fish...as the smaller ones are eating and doing fine. The big ones are staying right under the waterfall. When I examined the gills of the dead fish, they were the usual reddish color with areas that appeared bleached white...almost chaulky. I have only measured the oxygen levels at the surface...I imagine they are much lower at the bottom. Over the last month, the warmer it got..the less they ate, and the worse they looked. This really stinks!!!

[Akinosan]

Please check your submersible pump as soon as possible! I lost seven Koi last year when my pump shorted out! Also the survivors were all hanging out by the waterfall.

[gregbickal]

If the water at the bottom of the pond wasen't being circulated, it should have been cooler, thus having a slightly higher O2 content then the rest of the pond.

The pump running a new skimmer would have caused some surface disruption, which should have helped O2 not hurt it.

I also think that the O2 is not the problem. Have you scraped and scoped ?

[Brutuscz]

Problems even worse than I thought. My oxygen test kit was expired. I went out and bought a new one...level was 5. Not good. I went on the koivet web site. They stated hydrogen peroxide at a dose of 4 oz. per 100 gallons would bring up the oxygen levels for a few hours. I added it and am now waiting to see. wish me luck.

[JasonS]

The gills issue still says 'parasite problem' or perhaps chemical...

Double check your dechlor (maybe get fresh), airstones are good, but MOST IMPORTANTLY, check for parasites.

I hesistate to ask, because I don't like where my thoughts are leading, but are any of the smaller fish new? Were they quarentined at a good variance of temperatures?