Koi died after pond drained completely by accident

[stc60]

I had a terrible accident. The hose to my waterfall of my 900 gallon pond became unattached last night and completely drained the pond. I heard thrashing at about midnight and quickly rushed out. All 12 fish were thrashing about. I had no idea how long the pond had drained. All i could think to do was add water from the hose as quickly as possible. I did add a chlorine remover. After the level rose, the fish seemed to be doing okay. But, after about 20 minutes they all started to go belly up. By morning they were all dead. Very sad since I had a few for years. My questions are: Did my fish die from being exposed or a sudden dose of fresh water? Has anone else had this problem? What does one do in an emergency situation like this? yes, I know I need a pump that will shut off if the water level reaches a low point.

[Sanke56]

I would guess that the chlorine killed the fish. I have lost all my water a couple of times and topped it up with totally different water and the fish were fine. I guess you could look at the input water chemistry but that would be my guess chlorine. I have well water and lake water as a source at this point in my life it would be a good idea to have a supply of declorinated water to put them in in emergencies. Before you top up just in case something like this happens again. That is a very sad state of affairs but you must go on not looking back but learning a lesson from this experience anyone who has kept koi for a period of time is going to have one of these disasters happen. I lost my entire collection once to ice and no oxygen. The pump froze up too.

[aquitori]

I guess it was more the stress that killed the fish. Even if you added the water and conditioner it still puts your koi in a position to destress from the whole ordeal. How long were they trashing around until you heard them?....They could have been trashing around for hours....So it could have been stress.

[dick benbow]

Sory to hear of your loss! It does happen. I hope this incident will not take the wind out of your sails so to speak and discourage you. reach down inside and use the incident to encourage you to take positive steps to avoid it next time. A stainless steel hose clamp or two, a way to have the pump input run dry before the pond does. I commend you for having declor on hand. you would be surprised how many are not even prepared
to have something on the shelf. Thanks for bringing this subject up even tho your "tender" about it. maybe it will give others something to think about and prepare for so it doesn't happen to them. take consolation in knowing that if you have koi for any length of time things will happen. Just hang in there and move on....

[Rod L.]

Like Sanke56, I have this experience more than once also. Did the same thing, added conditioner and filled the pond back up and did NOT lose a fish. I would think that if you were to lose a fish from the experience, it would be over a few days and not all at one time over night. Therefore, I would suspect the feed water as the problem. Since you didn't say what product was used, a couple of things come to mind here. The dechlor was left outside in the heat and perhaps exposed to the sun and it degraded to point of being ineffective or more likely, your water source has added more chlorine to the system due to the season or other events, or you water source now contains chloramine and didn't in the past. If chloramine has been added to your water source, then your normal weekly water changes would not have caused your fish to react unless you did a large water change (the case you experienced with the drain down is a good example). Your filter probably handled this temporary increase in ammonia and life went on, but for a massive water change like you had to perform, there is NO WAY the filter system could handle it and the fish die from massive ammonia spike.
Either way, I would look at the dechllor agent as your problem. If you still have the product, test it to see if it is still good. Check with your water supply people to see if they are are doing anything beyond the norm lately in treating the water or have added chloramine to water.

Rod L.

[Werner]

STC60---

The easiest thing to do, so this never happens again, is to elevate your pump or pump pickup 1 foot from the bottom of the pond.