Very confused

First time overwintering fish in the pond. We had a cold winter here and I went out regularly to check my "babies". I left the pump running all winter and everything was fine. The pump died just a couple weeks before the final thaw and the pond froze over so I carefully cut a hole in the ice and dropped in an aeration stone and suspended it about 6"down. The fish still seemed okay. Within a few days of the thaw I noticed the smallest goldfish ( about 3/4") were dead. First day 1 fish, next day a few, next day a few more. then the bigger fish and bigger fish and then the biggest. Just 1 - 3" fish survived.( of course he is just a plain orange goldfish and not one of the "pretty" ones!) I'm not a technical type person and I don't know what type or size my pump is. I've never tested my water. I've always relied on the visual for determining if my water is healthy (fish behavior, clarity, algae growth, plant health, dragonflys and insects etc.)
Knowing I might run into trouble, because of never over wintering before, I did bring about a dozen various size fish in for the winter.
Any ideas?????

First let me say hello!! My name is Rick. I'm very sorry for your loss. Second, I personally think you should be testing your water regularly. You do know about the nitrogen cycle right??

Hey Rick,
Thanks for the quick response. I'm very embarrassed to say that I know nothing about nitrogen cycles or anything else "technical". I've had a pond for about 5 yrs ( put in a larger one every year of course! LOL) and my plants and fish have always done really well. I have never used any chemicals in my water or my garden. I do know that leaves and other organic matter breaks down and lets off dangerous gases. I did clean out all visible leaves and such every few days throughout the summer and fall. Shortly before the winter I went into the pond and tried to get as much off the bottom as I could. I never allowed the pond to completely freeze over for more than a day after my pump died. Does this help any? I feel like such an idiot for not knowing as much as I should and for allowing my fish to die!!

Sorry guys, but I did forget to mention that my 13 yr old nephew decided to "help" and drilled through the ice and into my flexible liner around the same time as the accident and there was some water loss. Maybe this plays into it somehow?

Well as fish eat they create waste and that produces ammonia which is toxic to fish. In the first weeks of setting up your pond with fish it builds up this ammonia. After a time and build up ammonia a bacteria forms that uses the ammonia for its metabolism and converts it to nitrite-NO2........ .Also toxic to fish. Now happens to come along another bacteria that uses nitrite and converts that to nitrate-NO3....also toxic, but much less so than either ammonia or nitrite. Also very easy to deal with. Simply changing the water when nitrates reach 40 is preferred. A 20 to 40 % water change should be done. Of course you would want to dechlorinate the new water. That is why you need a test kit for your water. I test mine 2-3 times a week, but I'm a little more fanatical than some. you should at least 1 a week. water quality is very important for fish if you want them to live out there full lives. If you've had your pond as long as you have said its already cycled and is in need of a major water change. Now I live In So. Cal so my wheather is mild so I am not sure about changing large amounts of water out of a cold pond but I'm sure someone on here could advise you on that. Good luck and if the whole nitrogen cycle thing does not make sense just google it and you'll get it.

Hey Rick,
Thanks again for the quick reply. I will definitely buy a water testing kit and start using it.
As of today I have totally emptied my pond of water, rocks and plants. I have patched the hole with some adhesive that the local garden center recommended and tomorrow I plan on scrubbing down the liner and each and every one of the rocks (just in case of there is some contaminate in there). I also failed to mention that my dog piddled on the ice whenever she thought she wasn't being watched! Do you think I'm doing the right thing?

P.S. Removing the rocks and relaying them IS my idea of fun !!! LOL !!!

So your totally starting over so cleaning is ok but only with water. When you introduce new fish just a few for the first few weeks until it has cycled. Maybe some comets or something. Try to really understand the nitrogen cycle and you'll be way ahead of the game. I would also put up some kind of barrier to keep the dog from piddling lol on the pond. That can't be good. How many gallons is your pond and what kind of pump and filtration do you have?? Also do you have any picture's??

Hey Rick,
I already plan to put up a barrier of some sort this coming winter. I also want to cover the pond in the fall to keep out some of the leaves. As to the pump and filtration, I'm really not sure as of yet. I mentioned before that my pump died shortly before the final thaw and I haven't purchased a new one yet. A friend gave me a pump they no longer needed but I haven't yet checked it out to see what it is. My old pump was just a regular looking thing with a foam filter on the side that the local garden center recommended. I also set up a very small preformed pond (on the side of the main pond) full of lava rocks and plants that I filter all my water through.
I try very hard not to get confused when you talk "technical" with me. After all I am just a mere woman!!!LOL!!!
If you could be kind enough to send me the formula, I will do the math and let you know how many gallons I have. I will also check the donated pump to see if it's suitable and if not I will have to scrape the bottom of the cookie jar and find enough money to buy a new one. Pictures pending!!!!

Here's a link to figure out pond volume. http://www.mystickoi.com/calc2.php

If its preformed its probably fairly small.

Cheers Rick

Your pic's didn't show up yet on the other post. Keep trying.

Hey Rick,
Thanks for the info. My pond is approx. 1100 gallons. My donated pump is a Hozelock Cyprio Titan 1450. The pond has a flexible liner. It is hard to figure an exact size for the pond because when I dug it I sloped one end and put stairs at the other for easy access. I will try to send pics again.