More aquarium trouble, Gourami with black spot?

[Deadcell34]

So over the past two weeks, I've been encountering one problem after another with my tank.

First, one of my platy's seemed to contract a serious fungal infection over night. He had 3 big bulbous white orbs on the bottom of his belly. Unforunately, he died before I could get the meds.

I decided to go ahead and start treating the tank with Proxima (I think that's the name, its a fungal treatment).

Well, yesterday I lost my other platy with no signs of distress. He just died. I observed him and couldn't figure out what was wrong.

In the process, I noticed my dwarf gourami has a black spot on his side (towards his tail). Any idea what it is? My first guess is ammonia burns but not sure.

20131101_103723.jpg Photo by D3ADC311 | Photobucket

20131031_190022.jpg Photo by D3ADC311 | Photobucket

My tank is a 10 gallon Marineland with 10 gallon filter. 10 ppm Ammonia, 0 ppm nitrate, 0 ppm nitrite. Tank has been established for 6 months with no problems until now.

 

[fort384]

Your pictures aren't coming through. I attempted to fix them but it looks like maybe their location in photobucket was moved? The URL is invalid.

 

[Deadcell34]

Just added links in place of the pics. Try that and see if it works.

I'm doing all of this on my phone and its proving to be difficult.

 

[FrankoQ]

Come again on the ammonia reading