My fish have all died after a new liner

[Brian maloney]

Hi everyone. I've had a 2800L pond for 3 months. I let the pumps and filters etc run for 4 weeks before adding any fish. I've only added 4 gold fish and 3 koi carp ( small ones). I somehow got a leak in the liner so I replaced it two days ago, added bacteria balls and chlorine killer as per the instructions and then re-added the fish yesterday, they were acting a little strange and now there all died apart from 2 goldfish which aren't looking good at all.
Water test results are.
NH3-0
NO2-0
NO3-0
PH-7
KH-2
GH-4

Has anyone got any advice?

 

[WaterGardener]

First off, running the pump and filter with no source of ammonia will do nothing but circulate the water. That is not what cycling means. Cycling refers to getting the nitrogen cycle established. There is plenty of information online and it's good to know all you can about that.

From your test results, your pond has not cycled and the KH is very low. KH should be 100 to 200 ppm.

What type of liner did you use?

 

[Mmathis]

Hello and welcome. I’m so sorry — it’s beyond frustrating when something like that happens. What were you using for a liner before you found the leak, and what did you replace it with? Did you find the cause of the leak?

Agree with what @WaterGardener said about cycling.

I suspect that the current pond isn’t cycled, and that when you changed out the liner, you took away a lot of the beneficial bacteria that was colonizing on that liner.

What did you do with the fish while you were changing the liner?

Also, you’re going to get comments about this anyway. Your pond isn’t large enough for koi. Your pond is perfect for goldfish. Koi need a lot of room, they produce a lot of waste, and they grow quickly. The general rule for koi is around 1000 gallons (or around 4000 L) for the first koi, then an additional 250 or so gallons (900L) for each additional koi.

 

[Brian maloney]

First off, running the pump and filter with no source of ammonia will do nothing but circulate the water. That is not what cycling means. Cycling refers to getting the nitrogen cycle established. There is plenty of information online and it's good to know all you can about that.

From your test results, your pond has not cycled and the KH is very low. KH should be 100 to 200 ppm.

What type of liner did you use?

I used a pond liner thats the flexible plastic type.

I've also added 100 ml of KH up to get it higher but it hasn't budged.

The lily pads have all died also but I'm unsure if that's just because they were out of the water for a day.

 

[Brian maloney]

Hello and welcome. I’m so sorry — it’s beyond frustrating when something like that happens. What were you using for a liner before you found the leak, and what did you replace it with? Did you find the cause of the leak?

Agree with what @WaterGardener said about cycling.

I suspect that the current pond isn’t cycled, and that when you changed out the liner, you took away a lot of the beneficial bacteria that was colonizing on that liner.

What did you do with the fish while you were changing the liner?

Also, you’re going to get comments about this anyway. Your pond isn’t large enough for koi. Your pond is perfect for goldfish. Koi need a lot of room, they produce a lot of waste, and they grow quickly. The general rule for koi is around 1000 gallons (or around 4000 L) for the first koi, then an additional 250 or so gallons (900L) for each additional koi.

I never found the leak so I added an extra underlay when i fitted the new plastic flexible plastic liner, i didn't no about the koi needing so much space either, that's something the shops should of told me.

I had the fish in a couple of buckets whilst replacing the liner which was for about 4 hours.

 

[AlyssaFish]

Being out of the water for a day will kill your lily pads, yes. In fact, they can die from being out of the water for a few minutes if it's a hot enough day.

Pet shops are generally worthless for good advice on pet care, unfortunately. At least in the U.S. anyway.

Most likely the fish died from the pond not being cycled properly, as everyone said, but it's strange to me that the ammonia levels are 0 on your test. Can you tell us a little more about the symptoms the living fish have, and how the bodies of the dead fish looked?

 

[j.w]

@Brian maloney
So sorry for the loss of your fish.

 

[poconojoe]

Sorry about your fish dying. That's horrible.

The liner of choice is 45 mil. EPDM which is a thick rubber, much like a tire inner tube. Second choice is HDRPE, which is a lot stiffer than EPDM, but is said to be quite durable.

PVC liners are horrible. So when you say a plastic liner, I don't know exactly what you are referring to. Most likely it's PVC, which coats much less, but doesn't last very long. I had one when I was a newbie. It lasted 3 months and sprung a leak. When I pulled it out, it was brittle and didn't have much useable life to it. So I hope you didn't go through all that trouble replacing the liner and ended up with PVC.

EPDM costs more than PVC, but it's well worth it. Believe me, I know. The money I wasted on PVC should have went toward a much better EPDM.

 

[TheFishGuy]

Sorry about your fish dying. That's horrible.

The liner of choice is 45 mil. EPDM which is a thick rubber, much like a tire inner tube. Second choice is HDRPE, which is a lot stiffer than EPDM, but is said to be quite durable.

PVC liners are horrible. So when you say a plastic liner, I don't know exactly what you are referring to. Most likely it's PVC, which coats much less, but doesn't last very long. I had one when I was a newbie. It lasted 3 months and sprung a leak. When I pulled it out, it was brittle and didn't have much useable life to it. So I hope you didn't go through all that trouble replacing the liner and ended up with PVC.

EPDM costs more than PVC, but it's well worth it. Believe me, I know. The money I wasted on PVC should have went toward a much better EPDM.

my pond currently has terrible 15 mil. pvc, in the spots where it has been exposed to the sun only after a few months it is already cracking and I will now have to buy a new liner when I redo the pond this year, I would have to agree with the fact that pvc just isnt where its at

 

[WaterGardener]

You can raise the KH with baking soda, sodium bicarbonate. You probably have some in a kitchen cabinet. The dose is one cup per 1000 gallons. It's best to mix it with water and pour it into the pond.

 

[Tula]

I'm really sorry for the loss of your fish and the trouble with your liner. I completely agree the store should have better informed you about the needs of the fish they sold you. It happens all the time and is so irresponsible of these stores!

 

[poconojoe]

my pond currently has terrible 15 mil. pvc, in the spots where it has been exposed to the sun only after a few months it is already cracking and I will now have to buy a new liner when I redo the pond this year, I would have to agree with the fact that pvc just isnt where its at

Uhgg, sorry to hear about your bad experience with a PVC liner.

Mine was in that brittle condition in about 3 months, and I live in the mountains of Pennsylvania, not sunny Florida. I had a horrible experience. Mine sprung a leak in the dead of Winter. There was no way to change the liner in that weather. I had to wait until Spring. Meanwhile, I had to keep my fish alive by adding 300 gallons of water every week.

Then while changing out the liner, my favorite koi jumped out of it's temporary holding tank and never recovered, even though I immediately picked him up. I was right there and recovered him, but he must have been in shock and died.

So, lesson learned...don't cheap out on the liner.

 

[TheFishGuy]

Uhgg, sorry to hear about your bad experience with a PVC liner.

Mine was in that brittle condition in about 3 months, and I live in the mountains of Pennsylvania, not sunny Florida. I had a horrible experience. Mine sprung a leak in the dead of Winter. There was no way to change the liner in that weather. I had to wait until Spring. Meanwhile, I had to keep my fish alive by adding 300 gallons of water every week.

Then while changing out the liner, my favorite koi jumped out of it's temporary holding tank and never recovered, even though I immediately picked him up. I was right there and recovered him, but he must have been in shock and died.

So, lesson learned...don't cheap out on the liner.

very much agreed! Im not in Florida, but I think with the snow, cold and hot sunny flucuations of colorado weather it may have caused some tough conditions on the liner....

 

[poconojoe]

very much agreed! Im not in Florida, but I think with the snow, cold and hot sunny flucuations of colorado weather it may have caused some tough conditions on the liner....

I didn't think of the fluctuations in temperature. That's a very good point.

I was thinking more about UV rays from sunlight and since I'm in PA and my pond doesn't get all that much sun, I was wondering how it could have failed so quickly.

 

[Brian maloney]

Being out of the water for a day will kill your lily pads, yes. In fact, they can die from being out of the water for a few minutes if it's a hot enough day.

Pet shops are generally worthless for good advice on pet care, unfortunately. At least in the U.S. anyway.

Most likely the fish died from the pond not being cycled properly, as everyone said, but it's strange to me that the ammonia levels are 0 on your test. Can you tell us a little more about the symptoms the living fish have, and how the bodies of the dead fish looked?

I'm assuming the ammonia level is zero because I'd just done a completely full water change. Some of the fish were swimming at the top as if there's a lack of oxygen and then the ones that are still alive are swimming on the sides and not using there left side fin. The bodies look fully intact but have lost there colour