Question on adjusting pH for different cycles

OK, I just finished taking notes on the Grow report #3. Zandor mentioned that some people adjust the pH levels at different cycles in the plants life (veg and flowering). So please clarify this and correct me if I'm wrong.
In hydro, the pH range is from 5.2 - 6.1
Nitrogen is available at a pH level of 5.5 to 7.5 (maybe even a little higher)
P is available at 5.6 - 6.5
K is available at 5.2 - 6.0

I know a plant needs more P than N in flowering. It seems to me that P falls in the same range as nitrogen. So what pH level is the best when flowering? When vegging?

And one more thing according to my notes...........
If calcium is available at a range from 5.0 - 5.5 and
P is available from 5.6 - 6.5 and
N is available from 5.5 to 6.5
how is it calcium doesn't get locked out if you kept the pH at optimal range for P and K?

the ranges are, i think youll agree, quite wide!
the idea is during flower the more P that can be absorbed the better! there fore to allow the ph to start at 6,5 and to drop over the next few days to 5,7 then hit it back up to 6,5 aagain!
this way the highter PH allows for more absorbtion of the P whilst the falling PH will allow for the other elements to be absorbed,
the prime pH for flowering is 5.7
however in the grow cycle the PH increases so the sollution is set at 5.5 and allowed to rise to 6.2 , this way thePH range is always within the requirements of the plants needs and in easy!reach for the plants!
the varieing PH is a good thing if controlled within certain parameters!the idea of altering the ph range is to optimise the easy accesability of nutrients to the plant! as and when the plant requires it.
also the ph as mentioned will rise in grow, and fall in flower!
there fore it makes sence to start at the opposite ends of the scale! in turn optomising the ph by natural process, altering the same too frequently, by adding PH corector, and trying to maintain a reading of 5.7 constantly!will only lock out nutrients and worsen the quality of the water!
hope this has been of some help!


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