Help req'd

eos9 · 27-12-2011, 12:07 PM

I am by no means an expert regarding Koi and would appreciate a little advice concerning an issue I have now experienced on two separate occasions.
I have a fairly small garden pond measuring approx 8ft x 4/5 ft in width.
At its deepest it is approx 4ft but taking into account various shallow areas prob averages 2.5-3 ft.
I was advised that I could keep a small number of Koi and to this end I have (had) 3 Koi (10-12inch) and 3 smaller Mirror Carp in my pond.
I have a 8000 ltr pump and waterfall which runs through a Fishmate 15000uv filter.
However on two occasions now my pump & waterfall have stopped working for a short period and within 2-3 days I have ended up with one of the Koi dead.
The cause of the pump not working was the electric socket tripping on the first occasion ( while I was away), whist this week the pump failed with a broken impeller.
On the first occasion this happened I took a water sample to a local Koi dealer and he found nothing too unusual about the levels etc.
He explained Koi could easily become stressed and this may have been caused by the waterfall not running for several days.
This week when it happened I noticed that the Koi were swimming close to the surface and were somewhat lethargic looking.
Bearing in mind the time of year and the fact that it was generally mild with some rain I wouldn't have thought It would cause an issue on this occasion.
I have taken a water sample and estimate the results as follows -
PH approx 7.5
PH high range - 7.4
Ammonia 0.25ppm
Nitrate N02 - 0ppm
Nitrate 2/3 ppm

Bearing in mind I cannot fully guarantee that the pump/waterfall won't ever trip or fail again at some point, Can anyone please advise what it is that is causing me to lose fish when my pump stops for 2-3 days.
It seems strange especially when I have been advised that it is Ok to switch the pump off anyway in the winter months.

Any help or advice very much appreciated.

Limey · 27-12-2011, 03:29 PM

okies lots more with better experience but will put my 2 penneth in...

koi near surface says oxygen.... link that to failed waterfall.... colder periods water holds more oxygen so that contradicts :/.

Even in the coldest periods people keep their filtration ticking over... it sounds like yo are maybe going natural wildlife pond that includes koi and small koi grow BIG...

Is the pond planted? lots of vegetation? You see the stuff saying oxygenating plants... now I think this is right someone else confirm pretty please... in sunlight plants will convert carbon dioxide to oxygen BUT in darkness [night] the opposite they use up oxygen converting it back to carbon dioxide... so at night and especially if warm [when water holds less oxygen] and you need that extra the plants are using it up... If you are heavily planted could e the reason... and surprised someone said you can just turn the pump off :/.

Look at filtration and oygenation methinks... an easy pod maybe... plus an air pump.... thats where I would styart I think can not have too much oxygen or filtration EVER imo.

Looking for the more knowledgeable to correct and add.

Hulley72 · 27-12-2011, 05:22 PM

Lack of oxygen would be my guess , especially without the waterfall running .

Doghouse Riley · 27-12-2011, 05:31 PM

A consideration is that if your filters stop working for any length of time then they start to become toxic.
A test? Turn 'em off for half an hour then smell them.

Davej · 27-12-2011, 09:13 PM

Hiya

When you only have a small amount of water to play with then things can go pear shaped very quickly.

If the failure happened when the water temps were cold then unlikely to be lack of Oxygen.

Your test results don't suggest anything obvious.

Parasites activity could be a likely cause, all be that it seems coincidental with the pump failure. The only way you can be sure is by a skin scrape; examining a sample of mucus from the fish under a microscope to see if parasites are present and if so which ones.

Dave

efficiencyman · 01-01-2012, 09:16 PM

Within hours of the pump stoping you will have much of the filter nitro somonas and nitrobacter dying off. This will often cause very fast toxic levels in the the 3 days your filter was off. Do not ever pump this toxic stuff back into your pond, flush it out a.s.a.p. to waste. Flush all media thoroughly and kick start with fresh media additive. As an electrician I would reccommend a separate RCD supply for each filter pump. I have 3 pumps from my 3 filters for reliability as sooner or later an RCD will be tripped if/when this happens and "you have all your eggs in one basket" you will be very lucky not suffer Koi losses, P.S. Condolenses on your losses

eos9 · 08-01-2012, 08:20 PM

Well thanks very much for the feedback. As usual these things always seem to happen at the worst possible times. ie on the first occasion the day after I flew abroad working for a couple of weeks.
Although the pump stopped due to a broken impeller on this occasion I didn't think it would be so much of an issue as a/ this was in December and weather was mild with some rain and b/ I have previously been advised that some people actually turn off the pump in the winter months anyway.
My worry is how I can avoid losing any more fish should this happen again in the future.

Quote:

Originally Posted by efficiencyman

Within hours of the pump stoping you will have much of the filter nitro somonas and nitrobacter dying off. This will often cause very fast toxic levels in the the 3 days your filter was off. Do not ever pump this toxic stuff back into your pond, flush it out a.s.a.p. to waste. Flush all media thoroughly and kick start with fresh media additive. As an electrician I would reccommend a separate RCD supply for each filter pump. I have 3 pumps from my 3 filters for reliability as sooner or later an RCD will be tripped if/when this happens and "you have all your eggs in one basket" you will be very lucky not suffer Koi losses, P.S. Condolenses on your losses