help needed a showa about 58 cm was slow in moving this morning not intrested in food late this afternoon fish dead on inspection gills almost white two days back i left the borehole on dam overflowed i suspect at least 60 % water change overnight this after the first two chambers were cleaned i think costia any other ideas?

Hi Gavin, without a mucus scrape and a microscope its going to be tough to say.

Hi Gavin

If it is parasites, then most likely Costia which cause the Gill tissue to die off.

KHV also cause white gills, but hopefully we do not even have to consider this possibility.

The last time I saw white gills was due to toxins caused by the seeds of a Seringe tree.

That makes me think that there might be some toxins in your borehole water. The fish could maybe handle a certain concentration, but could not handele the concentration after the huge water change?

Have you tested your borehole water? Any results?

I read somewhere that one should pump borehole water into a tank first and then heavily aerate it for 24hrs before adding it to a pond to get rid of heavy metals and things like that.

Just an after thought....no idea personally what could have gone wrong.

Hi Gavin

It could also be gass in yor borehole water. Any fine bubbles when you pump it into your pond?

Christie

Hi,

Let daarop dat as 'n vis doodgaan word die kiewe "wit"
As dit enige "gif" of ander element is wat die kiewe aanval sal meer vis dood gegaan het.
As die pH drasties verander het na die "Water change" sou al die Koi eers rusteloos en " ge'stress" voorgekom het.

Ek sal voor dat van die oorlewende Koi se kiewe ondersoek word.
pH verandering kan veroorsaak dat Koi oortollige "Musus" produseer, wat veroorsaak dat die kiewe hulle vermoe verloor om die Osmo-regulering te handhaaf. "Acidosis" van die bloed is die oorsaak van lae pH.
As die kiewe aan hoe pH blootgestel word (alkalinity) kan dit die kiewe "brand" , die vel beskadig en die oog lens en conia vernietig.

Al hierdie veranderinge veroorsaak groot "stress" op Koi en kan die dood van Koi veroorsaak.

Ek glo die vis het van skok dood gegaan!

Beslis nie parasiet probleem nie.

Maybe there is a simpler explanation -

Borehole water does not contain any oxygen.
Borehole left on all night.
Lots of new water without oxygen.
Also the bore hole water usually has a low pH. This rises as oxygen is dissolved into it.

Perhaps that one koi was not as strong as the others and died of shock - brought on by a combination of the lowering of the levels of oxygen in the pond plus a sudden lowering of the pH. We tend to forget that koi are individuals and as such react differently to their surroundings.

If you leave a tap on over night you pump in water with chlorine. You will see this when you find all the fish dead with damaged gills. But with borehole water you wont unless there is a 100% water change.

Borehole water is usually good for koi. Usually contains a lot of minerals etc.

Chris

Ja Swaer!