Sick Fish, [Shubukin] being bitten by other

Hi

First post here hope you guys can help me out.

To cut a long story short i had some type of infection in my pond
which after treating with all kinds of stuff didn't clear up and i was
advised to use Malachite Green / Formalin , which i have done. Two
does now 1 week apart so far, not sure if its working

I have 1000L pond, in the UK, My water conditions are good these were
the readings abotu 3 weeks ago:

Nitrite = 0 mg/l
Nitrate = 12.5 mg/l
Ammonia = 0.1 mg/l
PH 7

My pond now has: [i have lost 1 comet , and 1 gold fish] no fish loss
for a about 1 1/2 weeks

2 Shubukins [one very ill, big ulcer type thing]
1 sturgeon [looks ok]
1 comet [infected]
1 gold fish [infected]
2 orfes seem ok

My intial questions and reason i came here is:

The injured Shubukin seems ok sometimes ie swims around with the
others etc but it is being "attacked" bitten by the other shubukin ,
where the ulcer is , it doesnt seem to botherd by this, but im sure it
is as it looks to hide. However i took all my plants out as they were
rotting away.

What shall i do ? I can't really divide the pond as its one of those
rigid things all curved so its going to be hard.

Pics of the worst infected fish are he so if anyone could adivse if
the fish is recovering or it looks bad please do, One other person has
told me on a forum it looks likes its healing but im not too sure.

http://www.zaytoonmedia.com/illfish/IMAGE_00035.jpg

http://www.zaytoonmedia.com/illfish/IMAGE_00043.jpg

http://www.zaytoonmedia.com/illfish/IMAGE_00033.jpg


I have used a couple of other forums before i found this for advise
on the issue of the infection in the pond, so for background please
see these two posts...

http://www.tropicalfish.site5.com/tf...ghlight=waseem

and

http://www.uk.gardenweb.com/forums/l...1563768.html?9

As i said this is my first post so if i have broken any rules or
demanded too much from anyone i apologise

Waseem