[Worldwide Koi Club] Koi not eating and hiding
Hi Kim,
Have you been keeping an eye on the water parameters in your pond? When the fish died, you said they looked to be in good condition. Did you look at their gills at all before disposing of them?
I think it would be wise for you to remove the koi from your pond to give them a good inspection. Get yourself a small tank/container (maybe 10-15 gal in size), then place your koi in it so you can inspect them. If everything looks fine on their exterior, gently open their gill plates and see what condition their gills are in. Some unsafe water parameters will cause severe damage to the gills or the blood of a koi. Some parasites also attack the gills and will do severe damage to the gills.
When inspecting the gills, you should see very bright red, healthy gills. If you find they are a very dark color (reddish brown, or purplish) color, your nitrites in the pond are probably way too high. The high nitrites will cause the blood to thicken and they will no longer be able to efficiently separate oxygen from the water. In that case, the koi are basically drowning or suffocating because they aren’t able to breath. High nitrites is known as the silent killer because there are no outward visual signs that the koi is in distress other than their sluggishness and other abnormal activity.
If you find the gills are a very light pink or whitish color, you could have high levels of ammonia in the water, …. but usually with high levels of ammonia, there are other visual indicators on the koi that indicate they are in trouble. The white color indicated there is not enough blood circulation to the gills, so again, the koi can’t breath properly. High ammonia levels can literally burn the protective slime covering off of the koi, and will also burn the fins and gills of the koi on its way to eventually killing them.
If you find there are blotchy white areas on the gills, that’s a good indication of parasitic or bacterial infection. The blotchy areas are dead areas on the gills caused by the infection/infestation and is a good sign your koi are in dire trouble. The parasitic/bacterial condition must be treated very quickly, and even if they infection/infestation is stopped, the koi will most have a greatly shortened life time.
You should most likely perform a major water change to lower the ammonia or nitrite levels that may be present in the water (make sure the water you remove is being pumped/drained from the BOTTOM of the pond and not from the upper layers of water. Make sure your pond and filters are clean, then treat the water to correct the water parameters. Add salt at the rate of 3 cups per 100 gal of water in the pond. 3 cups of salt equals about 3% or .03 salt content and will allow your koi to tolerate higher ammonia/nitrite levels before serious damage is done to their gills. If you can find “Parasite Green” or “Proform C”, treat the water to get rid of possible parasites (they don’t kill all types of parasites, but do get most types) do a complete series of applications (following dosage instructions) until a full treatment is completed.
((CRITICAL NOTE: IF you use “Proform C” DO NOT add salt to the pond water.))((If using “Proform C” you can leave the biofilter system connected so the filter is treated too. IF however you use “Parasite Green”, you should bypass the biofilters for at least the first 4-6 hours after each application or the beneficial bacteria in the filters will be killed along with the parasites.))
If you find the ammonia/nitrite levels are way too high, you don’t have enough bio-filtration in your filter system (for the fish load present) or your biofilter has not become fully colonized with beneficial bacteria. At any rate, you might consider adding (doubling the size) to you current biofilter system. It’s much better to have more bio-filtration than is needed than to not have enough.
Hope some of this info is of help to your situation.
Don ikeepkoi
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Category: Philippines Internet Koi Society
