It's just strange that we had full size Koi for years with no problems. The babies are about 1" each. Thanks for the link on the newbie questions. I don't know a lot of these, but it tells us what we need to start testing for. I'll work on getting those answers. To start here is what we know:
Water quality
* Ammonia Level (pond) - need to get a tool to measure
* Nitrite Level (pond) - need to get a tool to measure
* Ammonia Level (tap water) - need to get a tool to measure
* Nitrite Level (tap water) - need to get a tool to measure
* Ph Level, pond (If possible, KH, GH and chlorine) - need to get a tool to measure
* Ph Level, tap water (If possible, KH, GH and chlorine) - need to get a tool to measure
* Brand of test-kit used and whether strips or drops? - will let you know when we buy all of the above.
Other useful information:
* Water temperature? - will check in the morning, but we live in Portland, OR and it's been around 100degrees this last week. But the first 2 fish died when it was in the 80's outside.
* Pond size and how long has it been running? 1100 gallons. The house was built in '86. I don't know how long the pond has been here. We bought it in 2007 and started having Koi in it 5 years ago.
* What is the name and size of the filter(s)? We wrapped the pump that sucks the water in with that thick black stuff and it goes through a filter that has a gravel bag and we wrapped that too.
* How often do you change the water and how much? We don't change the water. It rains here a lot so it fills up on it's own. When we go through a dry spell we'll add water, but we make sure it tests ok for chlorine before putting it in.
* How many days ago was the last water change and how much did you change? We've never changed the water.
* How many fish in the pond and their type? 1 full size Koi. Sorry, I don't know types.
* What kind of water additives or conditioners have you used? - that enzyme stuff to help get rid of the dead leaves and twigs on the bottom of the pond. We put that in once a week.
* What do you feed your fish and how often? 1x a day - 2 handfuls.
* Any new fish added to the pond recently? - 2 babies a month ago who both died and 2 babies a week and a half ago...one just died.
* Any medications added to the pond? no
* List entire medication/treatment history for fish and pond - none
* Any unusual findings on the fish? Our big Koi was "breathing" at the water line before we got the first 2 babies a month ago. We realized there was a problem with the pond so we scrapped out the bottom with the leaves and twigs and rebuilt the pump/fountain per the above description to make sure he was getting enough oxygen. We also started the enzyme weekly treatment at that time. That is when we got the first 2 babies.
* Any unusual behavior like staying at the bottom, not eating, etc.? Honestly, we've never seen our Koi eat. We sprinkle it out and this Koi nor the previous Koi we have ever seem just gobble it up in front of us.