As far as I know a high CEC or cation exchange capacity substrate holds the ions of ammonium, potassium, calcium and magnesium in a non-leachable form making them available for plant roots....never heard it 'stealing' KH? Maybe someone can enlighten me here.....
High GH will not affect a true softwater sp. It is almost always suggested taht the values for GH to be low for softwater sp but I tested this to be untrue with many of the plants I have. 1 example of one such test was using very high GH (21 GH) with my Mato Grosso for 2 weeks to see the ill effects and there was none. KH on the other hand at only 5KH was an issue after 3 days.
Aquasoil does more 'stealing' of the KH than anything else out there but this is a good thing you want with the more difficult plants.
The highest TDS I used with this Hygro sp Roraima plant was 420ppm while doing some tests and it looked great. TDS will not cause a plant to die as long as we are in a realistic range. BTW I use TDS as a gauge of the water quality I like to maintain not to gauge plant success. Too many factors affect TDS the greatest one being Potassium (K2SO4) then CaSO4, CaCL2 then Mg....this is not including the waste from our fish, plants...etc.
The 穀精 Junkie
Last edited by mrkookm; 08-22-2008 at 08:57 PM.