Fish died

[Annsabine]

Hi all,

I am a new fish caretaker and have been busy getting my basement overwintering tank set up ready over the weekend.
I was planning to transfer my fish to the new digs today. Unfortunately when I went out I found all but 2 of my baby shubunkin dead and 1 of my adults struggling at the bottom of the pond. My other adult seems fine. The 2 surviving juveniles also seem fine.
Could an overnight cold snap have killed off all of the juveniles and one adult but not the rest? Could it have been low oxygen? It seems so random!
Any insight into what could have happened would be helpful.
I’m a total newbie, but I’m educating myself as I go and am hoping the survivors will overwinter well in the luxury basement condo.

 

[Mmathis]

Hello and welcome. So sorry this has happened to you.

There is probably more going on. Can you tell us more information about your pond — how big is it, what kind of filter set-up do you have?

Also, where do you live?

 

[Mgessert]

Any water test results?

 

[Annsabine]

Thank you for your questions.

My test strips measured all in the safe range, but I don't have oxygen tests. I will certainly order them now!

I have a Pondmaster PMK190, but it was off for about 48 hours before the deaths. I am feeling pretty guilty about that, I was doing some rearanging of electrical cords to get the basement tank ready and thought they would be OK for a bit... Will low oxgen kill off most fish but not all? How did my 2 survivors make it?

My pond is about 75 gallons, only about 20 inches deep, and I am in upstate NY. There were 2 adults and about 10 juviniles in the pond.

Thanks again

 

[Jhn]

Test strips are unreliable. Did you cycle the current outdoor pond/tank before adding the fish? That is a lot of goldfish (even small ones in that size pond) it may not take much to push the water quality beyond a tipping point. How are you planning to cycle/ or manage the cycling process in your indoor set up for them before transfer? Ie are you moving over the filter from the pond to the indoor setup, adding live bacteria cultures ( be careful there are only a few products out there that are truly live the rest are useless) to try and lessen or shorten the effects of cycling process. If not you may lose fish just moving them over to another tank as the nitrogen cycle in your overwinter setup has yet to even start.

 

[WaterGardener]

It is often the case that some fish will die and some will survive. Generally, with too low oxygen levels, the larger fish will suffer the most, since they need more oxygen to feed their cells than the smaller ones.

 

[Annsabine]

I figured if it was the oxygen then both adults would have died and more little guys would have lived, the fact that only one adult and two little guys lived is what was most confusing.

I had planned to use the filter from their pond and was going to add 50% pond water when I transfered them.

I went ahead and just moved them to a full tank of conditioned tap water, since I wasn't feeling good about using their water (just in case) and I am using a different filter. I know it isn't ideal...

They are all in the winter tank now and they seem OK. I am keeping my fingers crossed.

I realize it was a lot of fish.. I honestly had no idea how many little ones were out there. I had already removed over 20 and found them new homes. I had also brought a few of the really nice looking babies inside to my pet fish tank.

I was not prepared for baby fish. lol

 

[j.w]

and welcome @Annsabine

 

[addy1]

I was not prepared for baby fish. lol

It happens and it happens a lot during the summer. I tend to quit feeding in the spawning season so they inhale the eggs.

This year feeding them so we do get babies, replace those the snakes are inhaling.

Welcome to the forum!

 

[WaterGardener]

Keep a close eye on your water parameters. Since you are starting with a new filter, your tank will have to go through the nitrogen cycle and you have no beneficial bacteria to take care of the toxins produced.

If you have Prime, or can get some, it will bind the ammonia and nitrite that is harmful to your fish, but only for 48 hours when you will need to dose it again. It will take several weeks before the cycle is completed and you have enough bacteria to handle the fish load.

 

[Annsabine]

Keep a close eye on your water parameters. Since you are starting with a new filter, your tank will have to go through the nitrogen cycle and you have no beneficial bacteria to take care of the toxins produced.

If you have Prime, or can get some, it will bind the ammonia and nitrite that is harmful to your fish, but only for 48 hours when you will need to dose it again. It will take several weeks before the cycle is completed and you have enough bacteria to handle the fish load.

Thank you for the tip!

 

[Mmathis]

With your pond being only 75 gallons, you are going to have to keep a close watch on the water tests and your filtration. Can you give us actual results for your tests?

 

[Annsabine]

With your pond being only 75 gallons, you are going to have to keep a close watch on the water tests and your filtration. Can you give us actual results for your tests?

I threw the strip away, but everything was in the normal range.
I did think of one thing, I have a black walnut tree near the pond and we have been fishing nuts out. I wonder if the chemicles in the nuts were at fault.
On the bright side, everyone in the basement is doing great.

 

[Mgessert]

I think you’ve nailed it. The juglone toxin in black walnuts is very toxic to fish and, in fact, has been used to kill and harvest them.