Koi Fish Information Centre

First… sorry about your loss.
Second, when repopulating your pond, please do not get any Koi. They grow much too large for a mini-pond like yours.. and the ones I’ve had. Koi need at least a 2,000G pond for just a couple of Koi. They grow to 3′+ in length and are big-time swimmers so a mini-pond is much too small for them. Your 700G pond would be fine for 10 or so goldfish and if you like the looks of Koi, look around for Sarasa Comet goldfish which have similar body markings but stay in the 12″ range so they’ll have swimming room in your pond.
Now to your current problems.
Give us your test results.. not just “OK”. Give us numbers for ammonia, nitrite, nitrate, pH, temperature, KH and GH if you have all of these and any others you may have.
Also give us your tap/source water parameters out of the tap. Also fill up a gallon jug with the same water and test it after 24 and 48 hours and give us those numbers as well. Most water source parameters will change quite a bit from out-the-tap to 48 hours so it’s good to know what your water will do once it gets into your pond.
Did you acclimate the fish slowly to the new water? What was the water parameters at the fish store compared to your own?
pH shock, temperature shock, osmotic shock, etc. are all things that could result in the symptoms you are seeing.
Further, you should return the Koi as I explained above.. they get much too large for your pond. That will help with the eventual cycling issues you will have in the coming days/weeks/months from starting over new. It might not be a bad idea to return all but one or two of the goldfish to make sure your pond is safe for them before risking all of the other fish.
When the chlorinated water got into your pond and killed your fish, it also killed all of the bacteria (both good and not-so-good) that was in the pond so your ponds ecology needs to stabilize and grow again. You likely have none of the “good” Nitrifying bacteria so your pond will have to go through the nitrogen cycle all over again as well. Your plants will help but goldfish put out lots of ammonia via gill function and osmoregulatory system (urine, etc.) so you will need to test your ammonia and nitrite levels on a daily basis until the pond has fully cycled so you can be prepared to do PWC’s as needed to keep the ammonia and nitrite levels at a low enough level. You can add about 5 tablespoons of salt (diluted with pond water first and then slowly poured back in) which will help against nitrite poisoning once the nitrogen cycle gets to that stage but the salt won’t prevent ammonia poisoning.
Do you have a filter system? If you do, you could run some fresh carbon for two weeks which will help remove other possible contaminants. Carbon needs to be changed out every couple of weeks as it becomes much less effective after that time in most cases… unless the water was pristine already.
Lenny Vasbinder Fish Blog - http://GoldLenny.blogspot.com

Category: Philippines Internet Koi Society