princessyin

Got home from work today and found 2 of our koi's dead.

One of them was about 15" long and the other was just a small one. The big koi was here when we moved so must be at least 5/6 years old.

Topped up the pond a bit yesterday with fresh water cos a lot had evaporated over the last few days. Do you think this what caused them to die?? The big koi all its skin was flaking off as i netted it- gross.

The goldfish all seem fine though, i'm just worried cos we have another big koi just as big and i don't want him dying on us too...

nufc1892

Get the chips on

princessyin

lol- normally they go down the loo but he's straight in the bin!

binmen don't come til Fri though and in this heat..... gross

David Lock

Sorry to hear that.

Could a Heron (or even cat) have got to them and attacked them?

Is the pond very sunny and, if so, is it oxygenated with some airstones or similar?

Have you done a water check? dl

princessyin

Couldn't have been a cat. The pond is sunk and got a raised decking level above. Another smaller koi was dead as well- he was only about 3/4" long though.

Haven't done a test yet. the other fish seem fine though?

Hoppy

I'm no experts (plenty on here are though) but I think the problem with dead fish in this weather is lack of oxygen. Is your fountain or whatever working okay?

I've just spent about 8 minutes with the hose on full just topping up today's evaporation and it's only a small pond - 6 x 6ft. Get the hose out and make as many bubbles as possible.

Having said that, all ours could be dead as the water is like soup. Daren't shove any more chemicals in it

Richard.

CharlesW

It's almost certainly caused by the heat. The hotter the water the less oxygen will remain dissolved in it. Try to shade the pond and/or aerate the water.

3 years ago there was a large kill of salmon in the River Dee in Aberdeen. This was caused by high water temperatures.

AllanB

Koi are more susceptible to stress than some types of fish and low oxygen is a big problem with weather like this. You need a decent pump to get the oxygen into the water.

Is the water clear as you can also get algal blooms too which can take impact the oxygen levels.




AllanB

scooby turbo

HI IN THIS HEAT THEY NEED FEEDING MORE THAN ONCE A DAY I AM FEEDING MINE 2 TO 3 TIMES ADAY AT THE MIN. I ALSO LOST AFEW AFEW YEARS AGO DOWN TO CATS NOW PUT A BLACK NETTING OVER IT AND THE CATS CANT GET TO THEM NOW . SORRY FOR ALL THE CAP. LETTERS JUST SEEN IT NOW . HOPE THIS HELPS

scooby turbo

All so keep the water moving water fall ect. uv fillter work well

Nicks VR4

Yeap heat takes oxygen out blue algue is not good either IIRC

Was carp fishing a few years back very hot few days owner got the fire brigade in to hose water hit up into lake to get some oxygen back in

He then hired a pump to squirt water into lake

princessyin

Pump is ok, and obviously cos i topped up the water last night it should of had enough oxygen to last til 24hours right?

We haven't got an algae problem, in fact our pond is pretty clear. I put a algae solution in the day before. our pond is quite big though, 3mx 2mx 1m deep.

We've got 2 koi left now

Apparition

There's also a very voracious virus doing the rounds. Several Koi farms have been hit. See today's press for more details.
Yve

andypugh2000

You say the pump is ok but are you talking filter pump or airstone pump??

You will need a dedicated air pump and stone running 24/7 in this weather or you will lose more, I got mine from orchard fisheries in washington west sussex, cheap as chips and keeps the oxygen levels nice and high

princessyin

Pump thats linked to the filter and has a UV light in it??? Adding more water in this morning to get more oxygen in.

Gordo

Depending on the amount of water you've added, it could be the fish were affected by chlorine in the supply. Better to only add small amounts each day rather than lots in one go or let the water stand (e.g. water butts) before adding.

Gordo

Shaolin

We have koi in our pond, we have a decent pump and uv filter etc with a decent fountain, is it a good idea to get an air pump ?...will it really help that much ? pond is approx just over 1000 gallons and we have about 12 koi.

andypugh2000

I cannot stress how important an air pump is in weather like this, if you value your fish I wouldn't hesitate to get one.

The other advantages of well oxygenated water is the ammonia levels etc are significantly reduced and toxins etc are driven to the surface and dispersed into the air inc chlorine from tap water after a pond top up.

When I first fitted my air pump and stone I had a thick what gundge on top the water which was excess protein in the water which was very toxic for the fish, I never knew this was there before

David Lock

I would say yes. I have one with about 6 airstones and keep it going all summer. You can get a test kit for O2 levels, not expensive.

Yve, Can you say any more about this virus? Most Koi viruses are introduced with new fish but this could be an airborne one??

Princess - I think I would try a 25% water change. Just divert pump return pipe to waste, if you can, and top up with fresh water. You can get some anti-chlorine stuff but in my view there are so many bugs in any pond that tap water chlorine is immediately eaten up and won't cause a problem. And, as above, get an air pump. Too much of a coincidence that you have lost some Koi during the hottest time of the year.

Gordo

David - how do bugs eat chlorine?

air is the answer - the capcity for water to absorb/hold oxygen drops rapidly as water heats up, so the more you can do to aerate it the better.

David Lock

Well as I understand it Chlorine acts as an oxidising agent and will react with all organic matter is the water - and there's plenty of that. My fish guru also comments that in any event the Chlorine will not get past the fish mucus being protein. But, as I said, you can get an anti-chlorinating agent; FreshStart is one produced by Interpet if you are concerned.

Andy Pugh above mentioned Orchard Fisheries and my pal Graham (01903 983586) can post out an Atman 4000 six stone air pump for around £45. I am NOT on commission btw. Excellent pump though.

dl

root

Chlorine is hardly ever used now, most water companies use Chloramine but doing a small top up in a pond shouldn't be enough to cause sudden fish death.

This might provide a clue. Sudden death of algae will cause a sudden drop in dissolved oxygen, partly because algae produce relatively large amounts of oxygen during daylight hours and partly because the process by which the dead algae decompose also uses oxygen.

For this reason adding algaecide to water already low on oxygen is not a good idea!

Kieran_Burns

iTrader: (1)

Found this little table:

Temperature (oC) Maximum Oxygen Content (mg/litre)
10 .....................11.28
15 .....................10.07
20 .......................9.08
25 .......................8.24

princessyin

just got home from work and yipee the fish are still alive!

Apparition

David : Can't recall all the details now, and the Mail(which the item was in) has gone in the bin. But it did say that this problem had hit several stockists of Koi and was a serious problem. Maybe the Mail website might have more info ?
Yve

David Lock

Thanks Yve, I suspect is was/is KHV virus. David

shooter007

may be a combination of lack of oxygen plus clorine /cloramine (may have stressed them to much)

princessyin

Oh no.....the other big koi looks a bit stressed.... These last couple of days he's been hiding under the decking or in the plants but this morning he was at the surface. Not floating or up for air he just looked sad i hope he's ok when i get back from work... is there anything i can do??

David Lock

The number 1 thing would be to ensure there is a good source for air as suggested many times on this thread. The simplest thing would be to buy an air pump with some stones, plug it in and off you go.

There are umpteen other things you can do when you have time such as check water quaility, partial water change perhaps. Also use a good quality food. Good luck. dl

princessyin

Ok i will definitely go buy an air pump this weekend. Just worried that he may not last the weekend...