I suspect lack of Oxygen, help

[Debs]

I have one largish goldfish in my 18 month old pond. This was his second winter in the pond although he was won at the fair about 17 years ago and lived in a tank until we built the pond. I added 3 small gold fish last summer but last week all three died on separate days within the week. My big old fish is looking a bit sad. I have got him out and looked him over, no obvious parasites etc. Fed him a bit of food and after 30 minutes I put him back in the pond. He seemed much better for a couple of days and now looks sad again. Could it be lack of Oxygen? I have a small solar powered fountain that is on and off all day each day. When the sun runs out I can run it off the mains. Its a very healthy looking pond in summer and I have all the right plants in there, although still quite small, except the Canadian Pond weed which is rampant. What is wrong with poor old fish? How do I increase the Oxygen?

 

[Tula]

There are several simple ways to add O2 to your pond. Use an aerator or add a small pump . If you use an aerator, make sure to cover the air pump with a flower pot , tote.....something to protect it from the weather. A small pump ( not placed on the bottom of the pond ) could shoot towards the surface of the pond, breaking the surface and increasing the O2 exchange.

Another simple idea, would be to make sure your fountain runs all the time, using the mains, when there isn't any solar power.

 

[Usman]

looks like some disease that other 3 came with and died then affected this old one too , i would recommend some antibiotic or medicine methyl blue bath
a single goldfish doesn't need that much oxygen specially it was living in it happily before , some times leaving fish in pond is better and give it time to recover , if it gets worst then do other treatment because it can get stressed while transferring

 

[Meyer Jordan]

Certainly not an Oxygen issue as the large fish would have died first.
It does sound like a pathogen issue but before any treatment can be applied, the health issue needs to be diagnosed. You need to know exactly what you are treating for. Can you closely inspect the fish for any signs of infection or parasites....anything that looks strange or abnormal about its body?

 

[Faebinder]

Yah the three are diseased and hopefully it wont transmit to him.

Change the water of the pond.. all of it if possible... treat the left over water with meth blue. Bring the fish in, and if it was my big fish I would use medicated food for two weeks. Preemptive treatment.

Next time you bring in 3 fish, quarantine for 2 weeks at least.

 

[Meyer Jordan]

If you opt to use Methylene Blue, you need to shut down your biofilter. This chemical will wreak havoc with your Nitrifying bacteria.

 

[adavisus]

If water temps are mild enough for the goldfish to want to graze, see if a tasty little earthworm gets him excited. Could be something as simple as a shortage of protein in his diet that got him sulking

If the scent of a snipped worm sends him into a frenzy of excitement, by jove, find another worm....