What is a good ppm range to stay at in soil grow?
i start at Ec0.2 = ppm 100 to 150,(Hanna), with 100mm tall seedlings, and on a sliding scale, exponential, avoiding excess salt build up in the root matrix, swinging the grow medium Ph to strong, from mildly acidic. As a result of overfed nutrients, fed with salty alkaline tap water.
I deliver an end of flower Ec@0.9........................ if it's an indica end Ec can be as high as Ec 1.2........................as Ec0.9 is for sativa's end of grow max Ec................. drop root stim when you see flowers at 10mm.............. Ph to match Ec also on the sliding scale upwards, starting Ph seedlings @6.2 end of flower, for me wk10-12 a Final Ph7.2 and final Ec is 0.9
here is the reason why................... nutrient uptake at correct Ph'es......... if the soil temp is 22c to 24c............ never less than 20c.......................Note; (All Ec's quoted are nutrient salt measures only) Do not include base water Ec...... notice below in an acidic soil, how @Ph5.8 or below (Mildly Acidic) the Phosphorus is the first to lock out of uptake Ph range, Mg just ahead of that, between Ca & Mg, there is a Ph switch over zone....... ALR
addendum; when seedlings first are whetted, in a 5ltr pot, used to select the final individuals.......... put the light you are going to use for the whole grow "Duel Spectrum" HPS or LED............... over the buried seeds, at a height above germ pot top that gives 18 to 21c........ at pot top................. and 18,000 to 25,000 "Lux"......... 8,000 to 10,000 lux is needed for minimum growth..........
Accordingly, the buried seed detects the UV & IR from above, and moves to that beat.................... once emerged, germ'ed, to the cotyledon leaves +2 fans, drop the light to 24-25c at plant seedling top, this nullifies, prevents stretch to a weak light source, making the seedling fall over from stretch with low light....... ALR