I know some people say they had great plants with tap water....I dont doubd that, however, using RO water, demineralized water, or distilled water, would be much better !
Regarding PH , I'd say 5.5 is alright. There are moments when I drop the PH to 5.2 and moments when I let it go up to 6.5: different nutrients become available at different PH levels. This does not mean to fluctuate your PH up and down all day everyday. Just dont freak out if it buffers between 5.2-6.2
<<<it looks like a cal-mag deficiency>>>
5.8 - 6.2 (oops missed the 5.8 by .1) No
lower and lower is worse then higher and effects the plant faster.....Test and adjust
every mourning at lights on!
Ok I get everyone says use RO, but I do know that FoxFarm requires "tap" water. There's not enough calcium and Magnesium in FF so it's necessary for the tap water. If you look at GH Flora Micro, there's one for tap/hard water and one for use in 0ppm water like RO.
As for the CalMag deficiency, could there be too much calcium in the water locking out Mg?
FF or anyone else for that matter never "requires tap water"!!!
It requires Ca/Mg supplementation ! You DON'T know exactly what is in tap water....ANY water over 150ppm should NOT be used!
What a label says about tap or hard water CAN BE very "off",,,,Like I said, You (and they) DON'T know whats IN that water!!
I used my local well water at a seasonal swing of 146 - 152 ppm and did ok. After a year I was reviewing notes from my other facility and saw to big a difference in yields (hydro and soil). I installed a high pressure/speed RO system and everything evened out.
If you start from 0 ppm and add your Ca/Mg (CALi MAGic by GH) at 5ml per gallon. Then you add nutrition and pH.....There is
less unknown "whatever" and the plant has only what it needs to grow! It grows better, bigger, faster,,,,,with only what it needs!
To much Ca? I would say no.....There are other compounds in the water giving it it's ppm.....That's what it looks like...and that could be related to the low pH!
Doc