I figure such plants would not be significant as they eat slow and by the time it is a bit softer by 1-3 degrees, it is time for another WC.... silly
It is frustrating enough that a weed like hygrophylla poliserma does not grow as weed in my tank(s) with controlled temp, high light, dosed ferts and injected CO2. It would be a big challange to find out what is wrong, because my tank is showing a dynamic result.
Some plants are doing good : vals (partial creasing but growing tall) crypts, swordplants, water sprite, ambulia, tiger lotus, anubias, ferns, moss, cabomba caroliana, etc.
Some are not (and some doesnt make it): small leaved bacopa, hygrophylla poliserma, milfoils, cabomba furcata,alternanthera, stellata, etc.
I will need lots of advise and experiences from you guys to find out what is wrong. I've already put out some factors and left with lighting, hardness and substrate as the questionable parameter. That is why I'm already running my other tank with different substrate to see if it is my problem. I'm sure there will be plus and minus noticed on both substrates.
If you generally think that 12 gH and 9 kH is acceptable for running a general tank like mine, then let it be that way.
*I do consider RO unit as a long term investment. For now I have to look for one that does not cost me an arm an a leg (I have seen so far which cost at least $1000). I can see that in USA there are lots of household RO for $100-200