New To Fishkeeping - Losing Fish (To Ich/white Spot?)

[Haggisman]

1. Water parameters. (ammonia, nitrate, nitrite, PH, temp', Hardness etc)
 
With the API liquid test:

• Ammonia 0
• Nitrite 0 
• Nitrate 20
• PH 7.0 

Water temp 28c 
 
2. A full description of the fishes symptoms.
 
These seem to apply to my black phantoms only:

• White spots like grains of salt all over
• Losing colour on fins
• Swimming listlessly, floating vertically in the water - e.g. nose pointing up or down, floating at an angle, getting stuck against the filter intake
• Death

My clown loach has a couple of spots on his tail, but otherwise looks healthy (although he spent all day sulking and hiding yesterday after I did a big water change, and scared the **** out of me the day before by sleeping upside down against the filter intake!)
3. How often you do water changes and how much.
 
Started off doing ~20% once a week, but the last week I've done 2 x 50% changes, one on Sunday (13th), and one yesterday (17th).
I don't think I've been doing enough gravel vacuuming (nitrates were at 80 when I tested on Monday

), so I did the whole tank including under all ornaments.
4. Any chemicals and treatments you add to the water.

• Fluval Aqua+ water conditioner for water changes, 1.3ml/10l bucket
• Currently Interpet White Spot Treatment (no.6). Added 20ml on Sunday and 20ml yesterday as per instructions.

5. What tank mates are in the tank.

• 8 x Black Phantom Tetras (3 alive, 5 now dead
  
  )
• 10 x Neon Tetras
• 2 x Dalmatian Molly
• 1 x Bristlenose Pleco
• 1 x Clown Loach 

6. Tank size.

• 220L / 48.4 Gal(imp) / 58.1 Gal (US)

7. Finally Have you recently added any new fish?

• 10 Neon tetras about 2 weeks ago

For the back story - please click here: http/www.fishforums.net/index.php?/topic/440985-advicepointers-for-a-newbie-please/
 
Last Sunday (13th), I noticed White Spot on one of the Black Phantoms. Being 4pm on a Sunday, the only place open was Pets @ Home, so I rushed out and grabbed the only treatment they had (Interpet no.6). I did a big water change, and then added the medication as per the instructions.
 
Since then, all the fish except for the Black Phantoms have been pretty much fine.
 
The mollies look perfectly healthy - I can't see any white spot on them, although given the fact they are covered in black and white spots anyway it's a bit hard to tell.
The neons & pleco look perfectly healthy
The clown loach is acting normal, but looks like he may have a couple of spots on his tail.
 
However the phantoms haven't been looking healthy at all; 2 of them seem fine, but the others have been just "floating". We've lost 5 in the last 24 hours. One was stuck up against the filter intake yesterday morning, found another dead on the bottom around midday. I did a big water change, vacuumed all the gravel and did the second dose of the medication.
 
Another 2 died during the day/evening, and I found another one dead stuck on a plant this morning.
 
There are 2 phantoms which look "ok" at the moment, although covered in white spots and one of them looks like his fins are damaged, the other remaining one is doing the "floating" thing - he'll swim around for a moment, then just go back to just drifting, nose pointed down.
 
Is there anything I can do to save these last 3 - don't want them to be completely wiped out

 
I've tried turning the temperature up as seems to be recommended, but it doesn't seem to be going above 28c. There's plenty of aeration in the tank - we have 2 airstones and a treasure chest that creates a big bubble every 30 seconds or so!
 
Anything else to try?

 
Thanks!
 
Edit: Images:
 

 

 

[fluttermoth]

Sorry for the late reply
 
Whitespot can be a tricky thing to cure; while the parasites are on the fish (and, in another part of their lifecycle, as cysts in the substrate), no medication can get to them, so you have to wait a while for the lifecycle to work through; no cure will work immediately on whitespot. Raising the heat helps speed up the lifecycle (although you can also kill ich with high temperatures, most fish cant take that sort of heat), but it still takes a few days.
 
There are also a lot of medication resistant strains of whitespot around, so you might need to try another type. You will need to do a couple of very large water changes, and run some carbon in your filter for a day, if you can, to get rid of the old medication before you add new.
 
I'm afraid in the meantime, there's not a lot else you can do