Hey mate,

There are atl east 3 things to check for: PH, Nitrite and Amonia. PH should be about 7.5 with Nitrite and Amonia both at 0. Depending on how established you pond is you should be checking these levels on a regular basis and doing regular water changes of about 10%. Forget about the strip tests as they are pants. You need to go for the liquid drop tests or the tablet form as they are much more reliable.

How often are they flashing - is it constant or just a couple of times a day? It's normal for fish to flash occasionaly - its just their way of having a scratch, but persistant flashing indicates further issues.

If its persistant flashing and since you've introduced new fish to your pond I would hazard a guess that you have white spot as this is most common. This is by no means conclusive, so I would suggest you net up one of your fish and take if for a painless scrape at your nearest koi centre. They will be able to identify the parasite and supply you with the correct medication. O you will also need to tell them the pond water volume in order to establish the correct dossage. What ever you do, do not be tempted to over dose as this can and probably will cause further issues and doesn't spead up the healing!

Good luck.


Thanks for the reply, kois flashing occurs usually after feeding, ph is 7.6 ammonia 0 and i still have to do a nitrite reading, new pond, new kois, turned off UV light for faster bacteria growth. I spot redness and white thing on the tail of my ginrin tancho sanke and im not sure if it was damaged or some sort of bacteria, thats about it the rest of my kois have nothing visible, just flashing. The kois are very active and eat regularly, though I have cut down the feeding to twice or three times per day. I will get a nitrite drop test tomorrow and inform you all on what is the reading. Also, I would like to ask if anyone ever tried using salt, melafix, pimafix to combat any koi symptoms, any knowledge on melafix or pimafix would be greatly appreciated! Thanks in advance!