Koi groete aan almal vanmore. Gister middag terwyl ek my koi voer sien ek my groot Ogon lyk of sy rooi kolle het. Ek vang haar en sien dat die rooi vlekke soos bloed tussen die skubbe. Ek haal my mikroskoop uit en neem 'n monster. Ek tel toe op dat ek die Costia parasiet het. Die boeke wat ek het beveel Acraflavine 30ml per 1000 liter water aan met sout 3kg per 1000 liter water. Ongelukkig het ek nie Acraflavine gehad nie maar wel Malacite green poeier. Ek het toe 0,1g per 1000 liter water gemeng en my extra suurstof pomp inwerking gestel. My sout meter wys dat ek op 4,2 per 1000 liter water staan.

1. Het ek die regte ding gedoen om die invormasie in die boek te volg?
2.Wat is die oorsprong van Costia aangesien ek geen nuwe Koi in my dam het nie.
3.Hoeveel behandelings moet ek toepas.
4.Sout of nie sout konstant in jou dam

Also known as Ichthyobodo, it is an external parasite that is quite difficult to identify, even with a microscope. You need at least a 200 x magnification to properly identify it, and one of these cheap R 300.00 microscopes is not recommended to identify Costia. It is one of the smallest parasites common to Koi hobbyists and is often overlooked on a slide.

When viewed under the microscope, it looks very similar to the tiny moving air bubbles in the water, except that the air bubbles will move into one direction, and Costia will move backwards and forwards, almost like bumping cars at a play park, trying to dig through the mucus on the slide.

Physical symptoms on the fish will be excess mucus production, lethargy, clamping of fins and scraping.

You will probably notice reddening of the skin and especially the fins. If you see that your koi hangs at the air stones or water returns, it is an indication of the presence of Costia.

Fortunately it can be eradicated quickly with a high concentration of salt(5kg/1000 liters), but if you don't treat early enough, you might loose fish, especially the small one, as Costia develops rapidly on small fish. A salt bath at 1 kg / 50 liters will also do the trick.

Other recommended treatments are Malachite Green, Potassium, or even Methylene blue, and a once off treatment are normally sufficient, due to the very short life span of Costia. I personally use FMC (Malachite green and formalin) if I do not have a high concentration of salt in the pond, alternatively only salt at a high concentration (5kg/1000 l) , being a much safer and more natural treatment without any possible side effects of other medication.

My microscope cost me 4k and I did pick the very tiny air bubbles up that moved in any given direction. For how many weeks must I have the high concentration of salt and must I put once a week for the next 4 weeks Malacite green

Christo, gradually get rid of the salt with normal weekly backwashes.

All costia should be gone within a few days. After you have increased your salt level to 0.5%, wait a few days and do another scrape to make sure they have been eradicated.

If any individual fish has already been affected badly, do the salt bath on them. (1 Kg / 50 liter)

It should not be neccesary to treat for the next four weeks.

Keep us posted.

Thank You. It is only the one fish that have the redness. This morning the redness was not as dark as yesterday. Where does costia come from?

Christo wrote:

. Where does costia come from?

Most parasites come from newly introduced fish, but also birds, frogs and even insects that visit one pond and then visit yours.

Plants can also introduce parasites to your pond.

You have mentioned that you did not add fish recently. However, most koi have a parasite or two. They cause no threat, but the moment the koi are under stress, they multiply and "take over".

Your koi might have had costia all the time, but it never caused a problem until the koi became stressed for some or other reason.

Often this trigger in the case of Costia is a deterioration of water quality or large fluctuations in temperature.

I battled with my water 3 weeks ago. It is 100% now. At least I know what could be the problem. Thank you very mush.