[DJT75]

Need some help with my fishy circumstances.

We inherited a 250-300 gallon pond when we moved house last year, I've grown to quite like it
but the fish are slowly dying off.

Everything's been fine since May 2007 until about 6 weeks ago. 2 large tench that lived on the bottom died within
a few days of each other & 3 or 4 other small-medium sized goldfish types have died also.

We took a water sample to the local specialist to test, they said it was A1, absolutely nothing to
worry about there & the lady said the deaths could just be to do with population of the pond
sorting itself out.

We estimated we had 2 large trench (12"-16"), 2 large goldfish (8"-10"), 4 medium size (6") & about
another 15 or so small fish including 2 little Ghost Koi (3"). The tench have been buried along with
about 4 others. 1 of the large goldfish (Jeff) I haven't seen for weeks, the 2 Ghost Koi I haven't seen
for months, the other large goldfish appears to be wanting to die but isn't. He's just floating around
laying on the surface on his side - everytime I place a large net around him expecting to scoop out
another corpse, he swims off for a while there stops still again, urns on his side & floats to the top?
I've read something to do with SBD (swim bladder disorder) on the net, but have only found solutions for
tanked fish & feeding them.

So any ideas what's happening in the pond & especially what this big guy is doing playing dead all day?

I think Jeff may have been had by the local Heron, his mate was grabbed by it & only saved when the
heron dropped him on the patio (we rescued him back into the pond). I have improved anti-heron pond security
since that traumatic smash & grab incident.

ps. I scooped a load of crap out of the bottom of the pond on the advice of the lady at the specialists
about 4 weeks ago.

cheers

[IronGiant]

Do you have a lot of blanket weed or vegetation covering the surface of the water? if so it may be preventing a healthy exchange of gasses, I lost a pond full of fish that way. If you have an air pump (fish tank one) it might be worth popping an air hose in to increase aeration. Also if a lot of leaves got in over winter they may be starting to decay as the weather improves so raking out may well have helped.

Dave

[Leej]

Is/was the water green? The reason for asking is if the pool has algae in it and it dies it can cause the oxygen to go out of the water.

[DJT75]

We cleared out everything that looked like decaying plantlife, there's probably about a 15-20% covering of the dark green seaweed type stuff (is that blanket weed? I'm not sure). I hook out & trim this down regularly so it doesn't get out of hand. We had a lot of the light green mush during /autumn winter but removed it all months ago.

WE have a pump that leads to a waterfall feature, the lady at the fisheries told us to either put it on in the evenings or keep it on all the time (not just on daytime only, apparently bad for the fish) during this time of year to keep enough oxygen in the water.

The pumped water coming from the waterfall is clear & now you mention it, as it falls it pushes the pond water away showing a dark green layer on the rest of the pond...So yes the water does appear to greenish...

[Miyazaki]

Get some pond snails sharpish. They love algae.

[kingfats]

Originally Posted by DJT75

We cleared out everything that looked like decaying plantlife, there's probably about a 15-20% covering of the dark green seaweed type stuff (is that blanket weed? I'm not sure). I hook out & trim this down regularly so it doesn't get out of hand. We had a lot of the light green mush during /autumn winter but removed it all months ago.

...

Hi DJT75.
The seaweed type stuff is indeed blanket weed i just hook it out,leave it draped by the side of th pond for a day (let any creatures crawl back into the pond) and then just chuck it on the compost heap.
Green water and blanket weed are both forms of algae which can be easily kept under control with thriving plant growth.
All the best.

[JohnG]

Do you have a filter system as well as a pump ? If not it might be that the fish are all growing and now producing more waste, but then again if the specialist checked for ammonia, nitrate, nitrite and ph then it should be ok. I have testing kits and test my water weekly from spring time until I stop feeding the fish in the winter.
I cleared all my blanket weed last month with a big dose of Eco Pure Gold. It's not cheap, but if you use enough of it you will get rid of the weed problem.

[DJT75]

So are you guys suggesting I shouldn't have any blanket weed? Or just keep it under contol like I have been?

I don't have a filter John, no. But I did scrap up a load of waste & muck from the bottom a couple of weeks ago just with a strong net.

There is also a huge amount of frogs sporn at the moment, not sure if that is causing any problems, I hear fish eat it..

[JohnG]

I normally just keep blanket weed under control as I can never get rid of it totally in the summer.
Sometimes mating frogs mistake the fish as as frogs and actually mount the fish and clasp it around the gills. This can cause the fish to die as they can't breathe if the gills are kept closed.
Scraping stuff out of the pond won't combat the waste products that the fish produce especially when they are feeding. It's worth asking what the woman tested the water for, clear water is no sign of healthy water, battery acid is clear but you wouldn't expect any fish to live in it

[kingfats]

Originally Posted by DJT75

So are you guys suggesting I shouldn't have any blanket weed? Or just keep it under contol like I have been?

I don't have a filter John, no. But I did scrap up a load of waste & muck from the bottom a couple of weeks ago just with a strong net.

There is also a huge amount of frogs sporn at the moment, not sure if that is causing any problems, I hear fish eat it..

Hi DJT75.
Bit of blanket weed is normal and nothing to worry about easily controlled by hand and nutrient removal through plant growth.
Don't remove too much muck from the bottom,because this is very important to the balance of the pond.
Fish will eat frog spawn that's why i don't keep any fish in my pond.
Spawn > tadpoles > frogs frogs are great for the garden they love slugs.
Cheers.

[WibXL]

For so many fish to die in that period for me points to either water quality issues either caused by the natural bacteria dying off or something toxic that has been spilt into the pond.

Really you need to be able to measure your own water quality so that you can see for yourself what the numbers are and act accordingly as the advice you get from shops can vary greatly in quality.

There is also something called the nitrogen cycle that you should make yourself familiar with and you will need test kits for the following to monitor it, ammonia, nitrite and nitrate. A filter is also highly recommended as this will help to circulate the water and provide a home for the good bacteria.

It starts with fish, uneaten food and rotting organic matter producing ammonia which is highly toxic to fish which at sufficient levels can cause death within 24 hours and at lower levels will cause chemical burns and irritation and burn gills which makes it harder to take in oxygen from the water which can cause the fish to gasp at the surface.

After awhile ammonia eating bacteria will build up and begin to reduce the ammonia levels but as a by product of this nitrite is produced which is just as harmful.

Luckily another bacteria will then reduce that and nitrate will be produced which can then be kept in check with partial water changes and plants will use it as food.

When testing the water any amount of ammonia and nitrite is bad and shouldn't be seen in a pond with an established filter and nitrate should ideally be below 25MgL.

A filter will provide a place for the bacteria to thrive, keep oxygenated and if it has a UV light will help to reduce algae as well.

EDIT: Forgot to say that when doing water changes or adding water to the pond you should treat it with a dechlorinator first as the chlorine/chloramine present in the water can kill filter bacteria and irritate your fish.

EDIT EDIT: If something has been spilt in the pond such as washing up liquid an active carbon sponge will sort it out but you'll need a filter for it to work well.

[DJT75]

Originally Posted by JohnG

I normally just keep blanket weed under control as I can never get rid of it totally in the summer.
Sometimes mating frogs mistake the fish as as frogs and actually mount the fish and clasp it around the gills. This can cause the fish to die as they can't breathe if the gills are kept closed.
Scraping stuff out of the pond won't combat the waste products that the fish produce especially when they are feeding. It's worth asking what the woman tested the water for, clear water is no sign of healthy water, battery acid is clear but you wouldn't expect any fish to live in it

I think she tested it for everything, had at least 4 test tubes with different colour something dropped into them, it's a proper place I took the water too.

Due the colder than normal temperature at the moment, we were also told not to start feeding the fish again until end of April. I had given them a tiny amount early this spring but they weren't really interested in it..

[DJT75]

ps. Thanks all so far keep 'em coming.

WibXL - how often would you recommend a water change, I hear you should change about a 1/3 by letting it overflow. Also, I have 3 large water butts collecting from the shed roof, these are full & an water top up comes from those via a hose already directed to the pond under some rocks & plants..

Only once have I turned the tap on the bottom the first butt & release some rain water into the pond when the level appeared to be a little bit lower. So I have used a hose or spilt anything to my knowledge..

[TeenSpirit]

Hi,
my Dad had a koi pond with similar problem - he had to invest in a big filter system with large tank buried behind the pond and the water filtered through shingle - very complex, but it sorted out the problem, but then there was the problem with the pump maintenance and the regular washing of the stones and scrubbing of the filters and vacuuming of the bottom of the pond to remove debris - think it all got too much and he recently filled it in

[kingfats]

Originally Posted by DJT75

ps. Thanks all so far keep 'em coming.

WibXL - how often would you recommend a water change, I hear you should change about a 1/3 by letting it overflow. Also, I have 3 large water butts collecting from the shed roof, these are full & an water top up comes from those via a hose already directed to the pond under some rocks & plants..

..

Hi DJT75.
If you have to do a water change in a pond (due to pollution) then your either over stocked or the filter is not working properly.
If you have a low stocking level,then aquatic plants in the pond will be enough for the filter system.
All the best.

[JohnG]

It's best if you never have to do a water change. During the summer I lose a lot of water due to evaporation from my main pond and just replace what I've lost using tap water and dechlor.
I always clean my filters using pond water.

[JohnG]

I'm feeding my koi at the moment every other day but with wheatgerm as it's easier for them to digest and doesn't produce as much waste.

[WibXL]

Originally Posted by DJT75

ps. Thanks all so far keep 'em coming.

WibXL - how often would you recommend a water change, I hear you should change about a 1/3 by letting it overflow. Also, I have 3 large water butts collecting from the shed roof, these are full & an water top up comes from those via a hose already directed to the pond under some rocks & plants..

Only once have I turned the tap on the bottom the first butt & release some rain water into the pond when the level appeared to be a little bit lower. So I have used a hose or spilt anything to my knowledge..

If the fish were in a tank then a good place to start is either 20% a week or 25% a fortnight and then check the nitrate levels and adjust accordingly, this will dilute the nitrate and replace lost minerals and trace elements that the fish need.

I'd have thought that would scale up for a pond but as I don't have one and it seems like such a waste of water I'd listen to the advice given by the pond owners on here and do what they say

I'm not sure about using rain water though as the couple of times that it was brought up on a fishkeeping forum I used to frequent it seemed to be frowned upon as the water could contain all sorts of pollutants and nasties. I have however seen it recommended as a good way to save water so you might want to have a search on it and then decide either way.

One other tip is that if you do buy a filter don't over clean it. It might sound strange as you'd think the cleaner the filter the better it'd work but you'll be removing the bacteria from it and causing yourself no end of grief as the filter has to cycle again. Just scrape the crud off and give the sponges a gentle squeeze in a bucket of pond water plus never clean more than 50% at one time.

[the whistler]

Its very tempting to feed your fish too early in the year when there is still a chance of frost. A brief warm sunny spell encourages the fish to feed and then a sudden drop in temperature makes them try to hibernate agian and the undigested food rots and causes bacteria. I don't have a pond now, but when i did I never fed the fish before late April or early May.

Early spring is the time most fish are likely to die as they are still quite weak from the winter hibernation and prone to bacteria.

[kingfats]

Originally Posted by WibXL

I'm not sure about using rain water though as the couple of times that it was brought up on a fishkeeping forum I used to frequent it seemed to be frowned upon as the water could contain all sorts of pollutants and nasties. I have however seen it recommended as a good way to save water so you might want to have a search on it and then decide either way.

.

Hi WibXL.
Rain water is the best way and of course the most "natural" way to top up the pond.
I don't think i've read one case of rain water causing any problems what so ever.
It's also nutrient free.

[moby125]

Firstly make sure you haven't put any concrete blocks into the pond, for a pump to sit on or baskets. As the concrete contains lime this will kill the fish, the best thing to use is the red clay pots.

Also how many plants have you got in the pond, a sign of a healthy pond is how well you're plants are growing.

I take it you have oxygenating plants in the pond;

http://www.worldofwater.com/planting_oxygen.htm

Also get some snails and mussels;

http://www.stapeleywg.com/product/ox...snails_985594/
http://www.stapeleywg.com/product/ox...snails_138731/

As for algae I found this was a good solution;

http://www.stapeleywg.com/product/fl...plants_154393/

let it cover about 2/3rds of your pond, is too keep under control by using a net.

PS If you have put any concrete blocks into the pond, I would change all of the water.

[Nimby]

This sounds like overstocking of a small body of water.
I vaguely remember the 1" rule: 1" of fish length per square foot of surface area.
Those fish most stressed by the conditions in a closed water system will die anyway.
Do you have autumn leaves falling into the pond and sinking? It all turns to mud producing toxic gasses.
Icing over usually means the end of the largest fish due to lack of oxygen and toxic gas build-up.
My present pond is only 10 feet square but over a meter deep.
One or two of the very largest goldfish always seem to die off first each spring at 6-7" long after any winter ice melts.
I bought a large submersible pump to remove the bottom mulm but haven't tried it yet.
I will wrap fine plastic garden net around the pump to stop too much wildlife being sucked up with the mud.

[JohnG]

My main pond is overstocked but I have 2 large filters running to compensate for that. You can overstock a pond if you are careful with filtering and feeding

[Nimby]

Originally Posted by JohnG

My main pond is overstocked but I have 2 large filters running to compensate for that. You can overstock a pond if you are careful with filtering and feeding

I don't doubt it but just wait until the climate thought police come round to admonish you for excessive consumption of "our" electricity.

A solar panel and 12 volt pump is the only safe way into the fishkeeping future.

[JohnG]

I'm not sure what you're talking about there as the filters aren't powered, they are just very large biological filters which have water flowing through them fed by one pump

[DJT75]

Just had a little scoop around the bottom of the pond to see if there were any other rotting plants I wasn't aware of & up floated Jeff . He must've died trapped underneath something. Huge goldfish, my favourite too...

Managed to clear away all the dark green crap covering the suface of the water too...

So anyone got any ideas about my last large fish & his sideways floating? Again today he swims off if approached but it appears to me like his just having a prolonged death...

[JohnG]

I have a goldfish which has always been on it's side due to a swim bladder thing but the only time I've known any of my other fish go like that was when I overfed them and the Nitrite levels were dangerously high. Fortunately they all survived but only because I took immediate action.
They can get a chill in the swim bladder and be temporarily affected like that as well I believe, but as my main pond is 6 feet deep they manage to keep warm enough throughout the winter.

[kingfats]

Originally Posted by DJT75

So anyone got any ideas about my last large fish & his sideways floating? Again today he swims off if approached but it appears to me like his just having a prolonged death...

Hi DJT75.
It sounds like swimbladder but it could be any number of diseases to be honest.
Once the fish become stressed and their immune system breaks down,your in trouble.
Low stocking,water quality and the proper enviroment,fish should live a disease free life.You said you checked the water and it was fine.........did you double check?

[DJT75]

Originally Posted by kingfats

Hi DJT75.
It sounds like swimbladder but it could be any number of diseases to be honest.
Once the fish become stressed and their immune system breaks down,your in trouble.
Low stocking,water quality and the proper enviroment,fish should live a disease free life.You said you checked the water and it was fine.........did you double check?

I think I might do another water check this week, I'm pretty confident the last one was done thoroughly but no harm in doing it again.

On the overstocking issue, these same fish have lived here happily for a long time, we know the previous owners, & although I haven't told them of the recent spat of deaths - they've never had any problems before...

The pond definitely isn't overstocked now anyway, it's very much understocked...

[WibXL]

If possible do the tests yourself (I recommend Tetratest kits) and post the results for ammonia, nitrite and nitrate on here. The majority of problems tend to be caused by poor water quality either directly such as ammonia poisoning or indirectly by poor water leading to stressed livestock which will reduce their immunity and allow other problems to get in.