Change of water / tanks will often cause some issues of stress as new tank might have had a lower TDS
and older tank with less frequent or large pwc
, lots of top offs, will increase TDS
, as all the minerals stay in the tank in evaporation and not removing much water and adding more in will indeed increase TDS
Ammonia needs to be lowered should not be above .25 and ideally 0. Not likely with many GF. Your tank is a large size but doubling the number will effect the load and tax the BB until it grows more to catch up.
Still GF are heavy polluters. FX-6 is reported to be a great filter. I have 2 fX-5 and like them very much. Dr. Tims, (I talked with him at a convention and he told me it was great stuff
) is said to be good as well but not a miracle, should help if the bottle was fresh.
+++ for Prime conditioner.
will be your friend and see if they don't perk up some.