I've seen posts about fish dying before and things to investigate and I have tried pretty much everything but I'm still stumped on my problem! I had a small preformed pond for many years (300 litres) which did incredibly well. I only had basic goldfish but they started breeding year after year and many got to a considerable size. I decided to get a bigger preformed pond - about twice the size (800 litres) - and transferred the fish and they all continued to thrive for 2 more years. Then they started to die off one by one. I tried draining and testing and couldn't find any cause at all. Eventually they were all gone. I drained and cleaned and started everything off again and bought 3 goldfish. Two of them died within days and one survived. Left for 6 months with just the one. Bought 3 more and they all died, leaving that original survivor again. That one gold fish is still going strong and I don't know what to do before getting some more. How is this one goldfish surviving when others I add and the 30+ original ones (that were originally thriving in the same pond) have all died. The larger pond is about 20 feet from where the smaller one was but as mentioned I had no problems for 2 years after the move.
Hi and welcome to fk My guess is that the original fish (you say 30) probably died because you were overstocked and ammonia and nitrites couldn't be dealt with by the filter properly also nitrates could of weakened the fish and left them more susceptible to illnesses . My guess for the first gold fish you bought after the original load died also died because of ammonia and nitrite issues if you cleaned everything out thoroughly because this could of killed of your filter bacteria . And my thoughts for the last lot that died is that nitrates were quite high in the pond and this shocked the fish and killed them. Of course like I say these are just simple guesses based on the info you have given and I know more about tropical aquariums than I do cold water ponds. Quite a lot of what I've said is dependant on filtration the planting of the pond the time of year the fish were added etc. If you can provide any more information we will have a better idea such as time of year the fish died what you were feeding , and the things mentioned above. I'm sure one of the cold water advisors will have a better idea though Coolrice
Thanks for that. Post was getting a bit long for a first one, so I thought a less detailed overview would be a good start. Long established fish were very healthy in the 300l pool, so I was surprised that moving them to a 800l would be a problem. And, as mentioned, they were OK for a couple of years after the move and continued to breed. The first few to die were the bigger ones, so I put that down to old age initially but they gradually all died over the course of last summer. I've run ammonia/nitrate/nitrite/ph tests and all OK. I have a combined filter/uv - hoselock 6000 (for up to 6000 litres) which should cope easily with my 800l pool. I also had frogs spawning/tadpoles last year and actually some frog spawn in there today. So basically conditions would appear to be perfect but goldfish (other than one!) are all dying in it!
Any markings at death? Did you notice if any disappeared? You say the readings were ok - what were they? Was ammonia and nitrite 0 and what was nitrate? Do you have any plants? Is there any rocks/stones in the pond if so did you add any new ones in the last few years? How deep is the pond? What happens when they die - is it sudden? Do they go floaty? Do they flick about? As detailed answers as possible and we may get to the bottom of this. How big is the final fish? Does he get on with the others?
I used the basic tetra pond kits where you compare the colour of the water (after adding drops) to a colour bar chart. Everything was at an acceptable level in that nothing stood out as being wrong - all readings seemed "OK".
I have two types of oxygenating plants (sorry not sure of names) and have experimented with leaving lots in place and thinning it right back. I have had a dwarf lily but not in the pond now. I have a water hawthorn and an arrowhead.
There are rocks in one end of the pond which I have always had as a way for frogs etc to clamber out. I often see them sat behind. These are natural stone - literally dug out of the ground - slatey types - and there are flats rocks all around the edge. I am in the tin mining county of Cornwall and I know that #OOPS#nic is prevalent in the soil but the house I am in, I have lived at for 15 years, so the soil is unchanged during the long period when my fish thrived.
The pump runs a waterfall and I have tried fountain and waterfall.
Fish show no signs of disease. Well, out of 30+ that have died there may have been an odd white spot on one or two or a warty bit on some of the very old ones I had! The new fish I've tried are swimming around one day and the next morning they are dead!
It would appear to me that it's some kind of poisoning effect but I cannot think where it can be coming from (bearing in mind I have part drained and started again 2-3 times) or how one survives if the water is poisoned! The survivor was 3-4 inches at first and is now maybe 5. Wish I could breed from him!
richlidd wrote: I used the basic tetra pond kits where you compare the colour of the water (after adding drops) to a colour bar chart. Everything was at an acceptable level in that nothing stood out as being wrong - all readings seemed "OK".
Do you have actual readings? Tests for ammonia and nitrite don't have an "OK" area: they are safe at a reading of 0 ppm. Anything above that is toxic to varying degrees depending on amount and in the case of ammonia also on the pH of the water. Nitrates above 40ppm are a concern.
The lasts tests were taken last year and I don't know the exact readings. You matched up colours to a chart and they all showed acceptable levels. I can remember ph was 7 (by my eye) as the chart showed 6.5 and 7.5 and I thought my green colour was in between the two. There was the tiniest, faintest hint of pink for ammonia which meant less than 0.1. I can't recall nitrate and nitrite other than the colours matched with acceptable/OK. I will try them again this weekend and feedback.
OK.New tests carried out with an NTLabs Kit. Results are: ph: 7.5 Ammonia: <0.2 (maybe 0) Nitrite: 0 Nitrate: 0 GH: 2dh KH: 1dh
I haven't come across GH or KH before but according to the test kit leaflet, lows values are "extremely dangerous to fish"! So is this likely to be the cause of the fish deaths or is it a red herring! We have very soft water in Cornwall, so I would have thought all fish suppliers would mention a need to alter these levels if these are a frequent problem?