Fish die off

[Mmathis]

Generally speaking, yes. A koi that is four years old and under a foot long would be outside the norm. A whole pond full of them would be really unusual. I would LOVE koi that stayed that small.

I’m glad things have settled down for you but I highly doubt aeration was the issue, especially since you mentioned the smaller fish were dying. Oxygen depletion will hit the bigger fish first. A 3000 gallon pond with a low fish load - doesn’t sound like an O2 problem to be honest.

The fact that the depth varies from 5 feet to “a couple of feet,” sounds like a red flag, as well. That could mean a difference of, say, 2000 gallons at any given time.

 

[poconojoe]

Ok I went and got a basic test kit (well - the only one I could find on a Sunday!) PH 7.5, nitrates and nitrite were negative. KH was 80, GH was 60. It did not test for Ammonia but the fish look much better and no new deaths. They are now active and eating. Perhaps the Aeration was the problem.

I think you need to test for ammonia.

I don't think you have described your filter.
You need a decent sized filter for 3,000 gallons.

And, how is your plant situation? Plants are an important part of your filtration.

 

[theboyzmom]

Ok I got an ammonia test. It was 4 so I have treated it. My filter is a All Clear G2 from the pond guy - rated for up to 3500. has a UV bulb in it along with two types of media (course and small) filters. It is designed to keep good bacteria.

 

[Lisak1]

FOUR? Like 4.0?

 

[WaterGardener]

I think you found your problem! How did you treat for the ammonia? And are you running the filter 24/7 as it should be?

 

[theboyzmom]

yes 4.0 ppm. I was shocked. When I got the test the lady at the pond supply place I got some bacterial ammonia treatment. I also ordered some ammonia lock online and it will be here tomorrow. Should I add more fresh water or let the bacteria I added do their thing?

 

[WaterGardener]

The bacteria you need won't survive being in a bottle without air, so that is not likely to help.

If I were in your situation, I would do a major water change asap, being sure to dechlorinate the water, if that is necessary with your water supply.

Is your filter running all the time?

You should also check the KH. That's a vital part of the system.

 

[theboyzmom]

The KH was 80 - my filter runs 24/7.

 

[Mmathis]

@theboyzmom Can you please post a few pictures of your entire pond? I’m still concerned about the fact that the depth varies from 5’ to “a couple of feet.” Do you ever add water when the level gets low? A pond at 5’ might be 3000 gallons, but the same pond at “a couple of feet” would be decreased by a lot….leaving the concentration of ammonia (etc.) to be higher. Also, depending on where you live a shallower body of water is going to heat up faster than a deeper body of water. Warmer water doesn’t contain as much oxygen.

 

[theboyzmom]

First one at instillation last two today.

 

[poconojoe]

First one at instillation last two today.

Nice pond!

 

[theboyzmom]

Nice pond!

Thanks. It is my happy place but lately it is driving me nuts. Thinking of emptying and cleaning it out and repotting and then putting fish in. Our local FD had in the past brought water from my 5 acre pond - which would be amazing.

 

[BKHpondcritters]

@theboyzmom Can you please post a few pictures of your entire pond? I’m still concerned about the fact that the depth varies from 5’ to “a couple of feet.” Do you ever add water when the level gets low? A pond at 5’ might be 3000 gallons, but the same pond at “a couple of feet” would be decreased by a lot….leaving the concentration of ammonia (etc.) to be higher. Also, depending on where you live a shallower body of water is going to heat up faster than a deeper body of water. Warmer water doesn’t contain as much oxygen.

I think she might mean that it has areas that are 2 feet & deeper areas that are 5'.

 

[poconojoe]

Thanks. It is my happy place but lately it is driving me nuts. Thinking of emptying and cleaning it out and repotting and then putting fish in. Our local FD had in the past brought water from my 5 acre pond - which would be amazing.

Most of us don't advise emptying and cleaning a pond out unless there had been a chemical intrusion or some other major pollutant.

By emptying and cleaning it out you kill off beneficial bacteria and biofilm and you will have to start all over again.

It will take a while to build all that back up and you will probably end up with an algae bloom resulting in green water.
Until your system has cycled and regrows the beneficial bacteria, nature will provide the algae to consume excess nutrients in the water.

 

[WaterGardener]

Lovely pond.

Sorry you are having difficulties.

Thanks for the info on your filter and KH. The KH is okay, but marginal and could be raised. Most of us aim for 100 to 200, so there is a large range of good KH values. Even more than 200 is fine.