Living Organic Soil, RO water, and pH. What's the deal here?

[optical]

Reverse Osmosis system is working at peak performance, pH from faucet at a near perfect 7.0 and a TDS/PPM of under 20

Have suffered deficiencies in previous grows and overwhelming consensus seems to say LED + RO water means additional Ca/Mg is a must

So I bought this stuff: https://www.planetnatural.com/product/camg/

and this stuff to adjust pH which is pro-beneficial:

After adding the CaMg+ from General Organics, the water pH plummets (NOT rises) to around 5.6 pH.

So what do I do? So much ridiculous conflicting information out there about people claiming with organics you don't need to pH.
Well are those people taking into consideration that other peoples untreated tapwater can contain chloramines and ridiculously high TDS? So those of us resort to RO. And then find out "Oh our advice wasn't meant for RO"..

Would greatly appreciate some advice! Thank you in advance

 

[Jimster]

If you are using living soil, Cal-Mag isn't as much of an issue as the soil itself is supposed to supply most of the nutrients needed, unlike a hydro or soil-less system (DWC and anything that doesn't use soil/peat,coco/etc). RO water will strip off your beneficial minerals, so depending on your local water condition, it may or not be needed. Cal-Mag can often raise the Ph due to the calcium component, but living soil is a changing environment, not just what you add in (like hydro/dwc). Additions can alter the flora/bacteria that break the soil down, so additives can hinder the process and cause unwanted issues such as flora die-off, unbalanced nutrients.
There is a TON of conflicting info, but there is also a TON of different ways to grow, so it's hard to make a blanket statement about what is good or bad. RO removes many of the minerals needed, so replenishing them should be considered unless your soil has enough of the minerals involved stored away for use during the grow. The most successful grows I have seen are also the simplest, so don't fret too much about NOT adding a bunch of stuff to your soil and plants. Living soil was an attempt to create a synergistic relationship between soil components, bacteria and related fauna, and the plant, like is seen in nature. Depending on the state of your living soil, the size of your container, size of plant, and water retention all interplay and any additions can throw the balance off.
What is your runoff Ph and PPM levels? Runoff will give you a better idea of what is going on inside the root zone. A foliar application of a dilute Epsom salts solution can help to supply magnesium without disturbing the soil Ph too much. In summary, adding Cal-Mag is an option that depends on your particular setup. Living soil should provide enough of everything, but every grower is different. Take some measurements and make your decision based on what you see.

 

[optical]

If you are using living soil, Cal-Mag isn't as much of an issue

Thank you for the reply! I forgot to mention in the original post I use a high powered LED light (HLG 550), and the combination of LED and RO is especially taxing on the plants apparently. Have read a LOT of posts that say additional Ca/Mg is required especially with the combination. Also, in my previous grow, I did develop deficiencies in flower when using simple RO water and nothing else!


Strangely, the addition of CaMg+ makes my pH lower, not raise. The RO comes out of the tap at 7 and after Ca/Mg+ application drops to 5.5

This is why I am unsure if I should pH up it back to 6.3-6.5 ?

 

[oldskol4evr]

how much cal mag you use,id take the gallon of 7. water and add 1 ml at a time to come up with the 6.5 desired ph,then check ppm see what mineral count is

 

[optical]

how much cal mag you use,id take the gallon of 7. water and add 1 ml at a time to come up with the 6.5 desired ph,then check ppm see what mineral count is

Oo, nice idea, what PPM range is considered ideal?

If a water has no chlorine/chloramine and a reasonable pH, is PPM still an issue?

 

[oldskol4evr]

maybe this help,i h

ave no clue were your plants are at or even what your growing in,but this is the hannah feed schedule at 500 scale

 

[oldskol4evr]

Oo, nice idea, what PPM range is considered ideal?

If a water has no chlorine/chloramine and a reasonable pH, is PPM still an issue?

ppm is what you are feeding,if you give to much you nute burn so ya it makes a difrence,if your using ro water i would for sure use the cal mag,at the very least i would bring my ppm to 150 with the cal mag then i would top the rest of my ppm off with the feed,chances are once you do this your ph is gonna be in range