[Coralbandit]

Ich.
http://www.skepticalaquarist.com/ichthyophthirius/
Best link and info I have found.
Know your enemy(please read).
Change at least 50% and start with kordon rid ich plus(not the herbal crap) if your tank will allow.
Otherwise best either using salt alone,or slowly raise temp to 86f if the fish will tolerate it.
I don't recommend mixing treatments(just pick one and kill the ich).

 

[Coralbandit]

I have a 30g. Cories, white cloud mountain minnows, and the mollies.
My cory's are actually growing in new barbles! I probably have about 20 mollies, mostly juvenile size still though. I try to clean the tank weekly, removing about 3 gallons.

Thanks again for your comments and help!

The cories don't like salt,but are sometimes sensitive to meds also.
Raise temp slowly as you say,over a day or two.
The white clouds are cool water fish(some cories also) so keep an eye on them.Add extra oxygen with an air pump if you have one,otherwise lower tank water level so HOB will splash alittle more returning

3 gallons a week on a stocked 30?Shoot for 10-15g a week if possible.
Your water quality is the issue IMO.

 

[Coralbandit]

The spots are falling off!
They are now multiplying in your substrate(possibly by hundreds or thousands!).
Vac the sub for waterchange to remove as many as possible.
It is ONLY while the ich is off the fish you can kill it.

 

[Coralbandit]

The paraguard looks good.
It is either the combo or individual use of ;M.green and/or formulin that is most effective in killing ich.
The paraguard has M.green.

 

[Coralbandit]

Need to follow directions on meds but treatment should last 7-10 days at least.
Mostly you should treat for 5 days after last spot is seen at least.
You likely have a lot more males then you think as they can suppress their sex while young for up to a year!Especially if there is a dominant male in the same tank(they release hormones that can stunt other males or at least warn them of his dominance).

 

[Coralbandit]

As far as ich goes I change water everyday and just re dose meds for the volume of removed water.
Many directions do not list this as a step but I have never had any issues with it.
This way you keep a little fresh water and fresh meds working on the problem.
I clearly use more meds over treatment time then maybe they say ,but I also think ich is pretty easy to kill.