Thanks for the link Darrel.Hi all,
Unfortunately you will have to keep <"changing water">. "Prime" might help, as it will <"complex some of the ammonia (NH3)">.
I'm very wary of <"controlled release fertilisers">, because "controlled" can easily <"become "uncontrolled">. I've had my <"own experience of this">.
If you have them? <"floating plants will help">, they aren't CO2 limited, so can make use of the extra ammonia.
I don't have floating plants but I do have Limnophila sessiliflora which grows quickly as you probably know. I will trim the stems and allow them to float. This will a. expose them to more light and b. as you say remove Co2 limit.
I don't want to run my own Co2 as I am aerating and it would be a waste.