# Pond disaster - help needed!



## helly1980 (Jan 6, 2011)

Hi

We live in UK in Leicester (midlands) and have a 3300 litre pond with about 25various koi. Fish have been in pond now for over 8 yrs. Pond was relined 2 years ago and had no major problems til early Dec 10. Temp dropped and we lost 5 fish - pump and filter were still running at this time - we were advised to turn the pump off to preserve pond temp. Pond froze over mid dec - we kept an air hole open by using hot water.

When pond defrosted fish seemed ok until 1 week ago when a large koi started swimming up side down, we took some water to be tested and was advised that pond was suffering ph crash. 

Readings were

PH 5.3
Ammonia 8
Nitrite 0

Also ran a KH test which showed there was no KH - we were advised that we needed to use a KH buffer to replace kh and bring up ph and were sold NT Labs KH buffer and to do treatment immediatly and turn pump back on but remove dirty water from pump first which we did.

The next day big fish looked loads better and started to swim normaly again. But since Tuesady he is swimming round on his side and there are 3 others of different varieties smimming upside down and hiding in corners.

I did a water test tues and PH was 7.5 Ammonia 0.5 and Nitrite 0.25.
I called the fish shop again and they advised a 1/4 water change which I did on Tuesday and this reduced the ammonia to 0.2.

I dont know what else to do as I have read on internet that raising the ph too fast - which we did - can cause stress.

Please advise as I am really upset that my fish are suffering!!

Many Thanks

H


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## Sled dog hotel (Aug 11, 2010)

My OH is not here and Im not an expert but we had the problem same time last year. Our PH is usually high (Because of the water in my area) The problem we had or we were told was the Ammonia high levels. Apparently it can burn and cause damage to the gills, Think we lost about 4 or 5. We did manage to bring down the amonia but lost another couple after but all the others survived and were/are still fine. We now put zeolite in a net bag in the filter which absorbs amonnia apparently. You have to wash it out and clean it every 6 weeks and then put it back in. Sorry cant be more help but as I noticed your Ammonia was high,thought it might be some help. All ours are Koi too by the way.


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## Guest (Jan 6, 2011)

Who told you to turn the pump off? The filter could have frozen up with the cold conditions we've been having and the filter bacteria still need oxygen. I've seen plastic filter chambers cracking due to the ice pressing from the inside; water expands when it freezes. The filter outlet should instead have been simply moved below the surface to keep surface agitation to a minimum.

pH swings can cause stress, as the fish have to acclimatize to different pH levels within a short space of time. Rather than using the NT Labs KH buffer, you could have saved your cash and used something very simple: bi-carbonate of soda or a bag of limestone chips (Calcium carbonate, CaCO3) draped over the side of the pond.

Unless the pH was dropping very quickly within a few hours, there must have been some detectable KH as the pH would be critically low (we're talking below pH 5.0). I'd suggest that you replace the KH test kit with a different one and re-test.

I'd keep a very close eye on the ammonia, as its concentration and toxicity rises tenfold with one unit of pH.


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## helly1980 (Jan 6, 2011)

Hiya

Thanks for your reply.

It was a friend who has a pond that advised us to turn off the pump as his has been off since mid nov and his fish are perfect. The pump and filter are running fine - the filter box is housed in the garage and we have lifted the pump now which we were advised by the aquatics place.

We do not have a kh test kit - this was done at the aqatics place but I think it might be worth picking one up now.

I also read somewhere that adding salt can help to clam the fish but Im worried about causing more harm. Any ideas??

Thanks

H


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