Re: Pond Fish Very Strange Behaviour -- 07/01/09
Thank you for the prompt response.
<<Quite welcome Marty>>
- Water surface agitation was definitely affected by the temporary loss of the one spurter. There is some agitation from the Bio Filter tube, and the hose that was connected to the fountain, but very little compared to before. The Bio also blasts out a stream under the surface to create a small current - but does not impact surface to bring down air.
<<This is helpful for distribution, but something to agitate the surface of the water to expedite gas exchange is really needed here. The very high oxygen requirements of these fishes, the small size/volume of the pond, and the warming weather all deem this necessary>>
I will get a replacement in place today. I will check out the Bell types from the local store.
<<Excellent>>
As for your other notes: I live in Vancouver Canada.
<<Ah! I would have guessed the UK from your spelling (I lived in Ipswich/East Anglia for 3 ½ years)>>
- The weather was very hot last month (for here) but this week has been cooler (70F +/-)
<<Mmm'¦ I can only dream of highs in the 70s for now. But I shouldn't complain, I do like the very long warm season here in SC (I've even managed to keep some of the zone-9 pond plants year-round)>>
Yes, the pond will become too small as the Koi get larger (even w/ Bio and UV) - I am building a much larger pond but am working out a design for predator protection (Herons and Raccoons are plenty here).
<<Ah yes'¦I too have Heron and Raccoon problems and can sympathize>>
Right now the Koi are about 8~9", and the Goldfish are about 5~6".
<<Nice, but also quite large for this pond>>
Thank you for your advice.
<<I hope it helps>>
I will let you know how it turns out.
Martinus van den Bosch
<<Please do mate'¦ Eric Russell>>

R2: Pond Fish Very Strange Behaviour -- 07/03/09
I added a Laguna 900 with Bell fountain attachment.
<<Very good>>
I was able to add the 2nd attachment to the one missing from my Bio-Filter (bonus). I also added an air pump and air stone (down 2ft).
<<A very worthy addition>>
The fish are back to their manic aggressive happiness.
<<Ah, excellent! So good to know this took care of the problem>>
Thank you for your help!
Martinus van den Bosch
<<Was my pleasure Marty'¦ Eric Russell>>

Pond fish very strange behaviour.   Again...  7/9/09
Great site btw.
<Thanks,>
I have been looking for answers to a very recent and very odd behavior of my pond fish (2 Koi and 8 goldfish).
Background
Pond is appx 3' x 6' and 2.5' deep w/1 ledge.
Pond has a bio-filter, and a UV-Filter.
Pond is 3 years mature, as are the fish (outside year-round)
No new fish in years, nor new plants in over a month.
Until now - the fish have always been very active and healthy - all of them.
They are fed high quality floating pellets - generally twice a day - enough for less than 1 minute of eating. (They used to eat like they were ravenous)
They also eat the floating pond greenery (though not as fast as it multiplies)
<Indeed!>
The fish as of this last week have almost all started congregating around the base of my bio-filter fountain shaft - essentially all touching the shaft (or very close to it) with their noses. They are no longer swimming around aggressively as they had always done. If I startle them, they will dart away and swim around for a bit, but will then return back to the fountain shaft.
<Hmm... when fish congregate around bubbling or splashing or otherwise strongly circulating areas of water, it's typically because water quality or more specifically oxygen concentration isn't sufficient. It's possible that during the summer your pond is suffering from an oxygen crisis of some sort, and the fish are compensating for this by finding the patch of water with the most oxygen. Typically, that's the surface layer or water, but it can also be around anything that mixes air and water.>
The only change that comes to mind in the past month is that I had another fountain/water spitter ornamental unit that actually shot water into the pond (the Bio Filter fountain is missing the top so the water just rolls down it) - which got plugged up late last week, so I removed it for now.
Could it be lack of oxygen?
<Yes.>
I have no idea why the fish are suddenly acting this way and I fear there is something terribly wrong that is not showing up in Ph, Ammonia, or Nitrate tests.
<If there's a lack of oxygen, biological filtration often suffers, but during the summer, plants absorb ammonia directly, so a spike in ammonia might not be obvious.>
Any guidance or next possible steps I should take are greatly appreciated!
Steps taken so far
1) 20% water change
2) Added some diluted Aquarium salt at that time
3) Siphoned the water from the bottom of the pond (to remove sludge)
Here is a picture of what the fish are doing (reduced to 400k as noted in guidelines)
Marty
<Would perhaps concentrate on clearing out the pond: removing sludge, cleaning any filter inlets and outlets, checking the biological media isn't all bunged up with sludge. I'd also look to see if the pond wasn't also overstocked; your pond is about 45 cubic feet, or about 336 US gallons.
That's not a huge amount for a pond, a Koi carp especially can use up an awful lot of space, and a common minimum allowance is over 500 gallons per Koi. Cheers, Neale.>

Re: Pond fish very strange behaviour. 7/9/09
Thank you for your response, however another gentleman from your company <Not a company, just like-minded volunteers...>
had already replied the other week.
<Oh, I see. I wonder how the message got into my Inbox then?>
Yes, it was lack of oxygen - I added an aerator, bell fountain, and cleaned up the biofilter - all is well now
<Very good.>
Marty
<Cheers, Neale.>