Sick Bolivian rams - is this internal parasites or something else?

[greentime998]

Hi all, I have a 30 gallon tank with Venezuelan cory cats, a bunch of guppies and their fry, 3 otocinclus, and a panda garra.  Tank is heavily planted.  2 months ago I got 2 Bolivian rams, one male and female.  They constantly fought and nipped at each other.  Last week I realized the male's belly was pretty hollow and he was hiding.  He also developed tears on his fins overnight - I think the female bit him.  Female still looked great and was very active. 

4 days ago on Sunday I dosed with 3 packets API general cure, then realized my UV sterilizer was still on, so I turned it off and re-dosed Monday and then Wednesday.  I plan to do another course in 1-2 weeks.  Now male is acting more alert, eating, and coming to the front of the tank.  He's also started producing lots of white stringy poop, which I assume is the dying worms?  Yesterday he had an isolated episode of strange jerking movements, which stopped after about a minute and hasn't recurred.

However the female is acting extremely lethargic - I think this started Sun or Mon?  Earlier today I noticed she was tipped forward with head on the bottom - I assumed she was a goner.  Then she got up again and started moving around.  I did notice a red spot near her eye, which I'm worried is a small hemorrhage.  She has no sunken belly or stringy poop at all.  What could be going on?  I'm wondering if she could be experiencing toxicity from general cure or a different infection not covered by praziquantel and metronidazole.  Male seems to be doing better after starting the treatment, but whatever is affecting her seems different.

Of note, I previously had apistogramma agassizii that died after a month of unclear causes (both suddenly started acting lethargic and then died).  I then got a dwarf gourami that seemed fine and then suddenly bloated up and died after a month.  However all other fish in my tank seem to be doing great, breeding, and laying eggs.  But I can't seem to keep any centerpiece fish alive for longer than a month!

Parameters:
pH 7.8
dKH 6
dGH 12+ 
Ammonia and nitrites zero, Nitrates 10-20 ppm  (I admit that recently I did have a nitrate spike of 40 ppm after not doing a water change for 2-3 weeks - my fault).  

 

^^ Female with red spot near eye.

 

^^ Male with sunken belly, stringy poo, and fin tears/rot.

 

 

[Colu]

With female with red spot near the eye that  looks more like an injury the male with a sunken belly could have wasting disease for that you would want to treat with expel p once a week for 4 weeks there could be a couple of things going on such a parasitic infections and aggressively between the male and female that will be stressing them out leading to a reduce immune response I would separate them and move the male to quarantine tank  if you have @greentime998