Ok, so my 3 oscars developed HITH and I've been changing the water
more frequently, adding a more varied diet, adding another filter,
removing all the carbon, raising the temp, adding vitamins to their pellets
and treating with metronidazole.
But I noticed that the PH is like less then 6. I only have a mid-range PH
kit and it only goes down to 6 but the color of the test water is yellowish.
I'm thinkin that its like 5. Are my oscars under alot of stress and thats why
they have HITH? What can I do?
Maybe I should remove all the plastic decor in the tank and then do a big
water change.

more frequently, adding a more varied diet, adding another filter,
removing all the carbon, raising the temp, adding vitamins to their pellets
and treating with metronidazole.
But I noticed that the PH is like less then 6. I only have a mid-range PH
kit and it only goes down to 6 but the color of the test water is yellowish.
I'm thinkin that its like 5. Are my oscars under alot of stress and thats why
they have HITH? What can I do?
Maybe I should remove all the plastic decor in the tank and then do a big
water change.

like why does an orca's dorsal fin flop over in captivity?? just on of them thing that happen when a creature is taken out of the wild.