Largish White Spots

[ATK!!!]

Hello there, sadly today I woke up to find one of my Ember Tetra has some kind of white spots on one side of its body. The spots are relatively large (slightly over 1mm) and seem to be raised from the surface of its body by a considerable amount. At first I thought it may be fungal, but under closer inspection the spots are not hairy looking and seem to be smooth. I'll fill out the details for help:
 
 
 
Tank size: 180l Juwel Rio
pH: Fluctuates between 6.6 and 7.0
ammonia: 0ppm measured with liquid tests, the Seneye measures it to be 0.006ppm which is a spike compared to the usual reading of 0.001ppm. Perhaps due to a recent disturbing of the nutrient rich plant substrate
nitrite: 0ppm measured with liquid tests
nitrate: Between 20-40ppm
kH: Unknown
gH: Unknown
tank temp: A few days ago there was a heat wave bringing it to 26.5C, it has since dropped to 23C

Fish Symptoms (include full description including lesion, color, location, fish behavior): Two large white spots. Slight inflammation of one eye similar to popeye but much more mild. Streaks of blood around spots. The fish is actually behaving normally and is not breathing heavily or rubbing/ any other unusual behavior. It is also still eating food.

Volume and Frequency of water changes: 10% on every Saturday and 10% on every Sunday. I have done such small changes for 2 years with this tank without any trouble with ammonia/nitrate levels and the fish have been fine with this so far (I have a very high plant mass >85% area covered)

Chemical Additives or Media in your tank: Normal filter media and active carbon, occasional dose of Easycarbo/ micronutrients

Tank inhabitants: 20 Ember Tetra, 6 Peppered Corys, 3 Splashing Tetra, 1 Whip tail catfish and 2 nerite snails

Recent additions to your tank (living or decoration): A piece of sumatran driftwood

Exposure to chemicals: None

Digital photo (include if possible)
:

 

 

 
Sorry for the blurry images but it wouldn't keep still or show its affected side to the camera. Hopefully someone has some ideas as to what it is/ what to do?

 

[ATK!!!]

An update: 
 
The tetra is still alive but seems to be struggling, I did another water change and decided to dose some Interpet no.8 which is supposed to be antibacterial and antifungal. The active ingredient Phenoxylethanol is apparently also an anaesthetic so I'm not sure what this will really do. The fish itself is breathing more heavily but its spots remain the same. It is also pooping out white stringy stuff but I'm assuming this is just because it nibbled on a plant. Does anyone have any clue what these spots could be? Should I raise or lower the temperature to combat them? I'm at a loss here guys

 

[SeaGoddess]

I wanna say ich if I were you I would immediately remove this fish and do a large water change and treat with melafix and hope that he hasn't already transfered it to your other fish

 

[Ny82]

It's hard to tell if it is ich. When my tank got ich, it was very tiny pin head size spots on fins and tails. They would flash a lot too. It cleared within 2 weeks of dosing with salt and high temps. I lost a lot of fry and a few adults but surprisingly the cories survived.
I'm sorry I really don't know by looking at the pic if it's ich I have been trying to find pics of my fish when they had it, but that's the first thing you think of if you see spots. Hopefully someone else will be along to help. Could be fungal?

 

[DrRob]

Looks more like a swollen area, which to me would be a secondary fungal infection.
 
I'd quarantine, apply lots of clean water and maybe something like melafix.
 
Doesn't really look like ich to me.

 

[Ny82]

Looks more like a swollen area, which to me would be a secondary fungal infection.
 
I'd quarantine, apply lots of clean water and maybe something like melafix.
 
Doesn't really look like ich to me.

 
Yeah I didn't think it was ich. In my experience it was tiny dots and mine only had it on the fins. I'm glad someone else came along to help!

 

[ATK!!!]

Well today the white spots seem to have disappeared. In their place are two rather red patches on the affected fish and a slight white sheen over a small part of its body (I think this is probably the remains of the secondary fungal infection you guys were talking about). Also I don't know if I'm just seeing things here but there seems to be a minute little brown circular thing attached to the fish by the affected area?! Any clues as to what it could be? 
 
In the mean time I'll do another larger water change and try to get some kind of quarantine bucket ready.. I don't have any spare pumps or even aerators so how do you people propose I do this? Bearing in mind that I probably wont be able to get to any fish shops until the end of tomorrow when my parents will be around.

 

[DrRob]

With no spare pumps or heaters leave the quarantine thing for now. A small heater and a small box filter that you can pinch a small amount of established media from your main tank is all that you actually need, so they're easy enough to sort out in the longer run. Keeps dosing of any meds away from the main tank, meaning that you can use heavier duty stuff, allows different water treatments and easy frequent water changes and possibly most importantly it stops the others from eating their weakened colleague, but it's not the end of the world. Lots of good, clean water is my general cure all otherwise.
 
I'd need pictures, if you can get them, to advise on the brown thing.

 

[ATK!!!]

I'll attempt a picture soon, I'll try and find the macro lens to get a better image. Thankfully the tetra seems to be staying well away from the other fish at the moment so I hope this will lower any risks of it transmitting things through physical touching. As of yet no other fish are affected thankfully. The water is almost warmed up and ready for another change

 

[ATK!!!]

Here's the picture although its not all that helpful. I edited the colours to make it stand out more so that's why the fish may look a little strange: