ok thanks for the info, that helps a lot! i do have a couple initial questions/suggestions:
-what is a "PNT"? i hope it isn't referring to a pig-nose turtle aka fly river turtle...as these should generally not be kept with fishes, and just about all turtles will eventually shred up gars. then again, i am only guessing at the PNT definition.
-bioballs work just fine for freshwater...was it a saltwater person that told you not to use them (the latter part of the statement is just out of curiosity)? anyway, i would replace the filter floss/wool in your filters with ceramic rings or bioballs...the wool accumulates crap much more IMO and looses efficacy rather quickly when this happens...its also going to trap a lot more waste which can lead to spikes, etc.
you won't want to remove and replace all at once. i would suggest removing a portion of the wool OR if there is empty space, place the rings above or below the wool (whichever way runs the water through the wool first) that way the bacteria from the wool can readily colonize the ceramic rings/bioballs. after several days/a week of leaving it like this, remove the wool and just keep the bioballs and rings. you could still use the wool in some places, but i would replace it each month as it's just going to trap garbage.
30% every other day is good for now until things calm down in the tank. keep checking the water, at least once every few days. check the pH before AND after a water change and let us know the results on both.
eventually you can moved to water changes just once a week, but i'd say keep the present regimen for at least another full week--
--solomon