Nutrient Discussion

Im a newbie as well, but thus far, between the fox farm recipe, cut in half as suggested by most seasoned growers, and tips from ilgm forum members, my girl seems to be happy. Ph im still struggling with. Now waiting on ph up to be delivered as last batch went way down after nutes. This forum will be a huge help to you as ive found out ! Im starting a new grow soon with a journal and will tag you in for the ride and info i gain !!

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If you dont like spending money on ph down and up use lemon juice or vinegar as ph down. And use baking soda as ph up. Saves a ton of money and I have been doing it for years. And in that FF trio I dont use the schedule. Any time I got my plants run off any where near what they suggest I would get a lock out. I try to stay around 1000ish ppm on run off. Well lower for seedling. Just be careful getting up around 1700 to 2000

May need to clarify medium used. When I used the trio and fox farm ocean forest I would always be 2000+.

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Sorry that was a coco grow. See what happens when I respond to thread at 4 am

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@beardless the measurement of PPM is what - simply the PPM in the Nutrient H2O?
Why did you change PPM from 700 to 500?
Adding nutrients to H2O of ~223 must then be calculated/adjusted. No?
I will need to begin feeding “soon”. I intend to use ‘Zero Water’ H2O ™ that has very little (<15PPM/TDS Vivosun meter) and does not affect normal Tap water pH - so I can adjust accordingly before adding nutrients.

I watched the video for Runoff H20. It was only specific to pH, but not TDS related to nutrients. Still confused and searching for clarification.

Yes parts per million or another term is TDS total dissolved solids. The measurement after nutrients are added therefore includes all elements / nutrients being measured. Those in the nutrients themselves and the water.

No. If the target feed is 1000 ppm this includes everything in the water and nutrients. People with really high water ppm will often install reverse osmosis systems. This allows for more nutrients.

I changed because my pens use the 500 scale. Lets say I just mixed up a batch and checked its PPM. My pen reads 1500. Then I look at fox farms feed schedule and it says my PPM for week 4 should be 2100. Both numbers are correct. 500scale X EC of 3 = 1500. 700scale X EC of 3 = 2100. If I was trying to match the 2100 PPM on FF schedule I would be overfeeding them by 40%. When I did the schedule I had a cheap pen and I could not change the units of measure. It would either read EC or use 500 scale.
I upgraded my pen to a Blue Lab conductivity pen. With it I can change to the preferred scale or EC.
I hope this made sense.

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@beardless; thanks for the explanations.

  1. FWIW; after discussion with @SpinyNorman, I believe, I’ve tested pH and TDS of Zero H2O filtered water and found this - although the TDS tester that comes with a Zero Filter, they’re not as accurate as a Vivosun TDS meter. And, to the pH topic, the Zero filter only changes the pH by <5%. So I’ll be using Zero H20 Filter to remove 90%+/- of solids and can gauge my feeding reasonably accurate (-25+/- TDS).
  2. The Pens…okay, yes I understand mostly, but will need some more experience to fully “get it”.

Another FWIW: I used Fox Farms pH and TDS testing criteria, and an email or two with their support folks, and found (if my Vivosun is accurate) that Straight FF Happy Frog out of the bag has pH of 7.20 and TDS of 450 (distilled H2O and 1:5 ratio soil to H2O).

I’ll be testing the HF+CN soil tonight and expect to get some nutrients into soil tomorrow, when they’re scheduled for a watering.

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Okay @Beardless; still trying to understand the 500 to 700 Scale. My Vivosun pen can change between EC and PPM. However, I really don’t understand the correlation between EC and PPM.
I see in the FF chart: Week 4 EC: 3.00-3.40 and PPM(700 Scale) 2100-2380.
I suppose I’m slow on the uptake. I simply don’t understand what Scale my Pen uses or is calibrated to.
Vivosun doesn’t provide the information - not that I can find anyway.
Thanks again

With your pen set to EC, take a reading. What does it say?
Then change the mode to PPM. If need be take another reading. What does it say?
you will be able see what scale is being used

EC of 3 x 700 -=2100
All I am saying is if you pen reads in 500 scale it will show ppm of 1500. If you think, to get the proper nutrient mix you need to add more nutrients to get it up 2100, it would be a mistake. You would be over fertilizing.

@beardless ; did some transplanting (again) and the 1st real feeding at week 4. What a damn shame and mistakes abound on my 1st grow.
I did 1/2 strength FF: Big Bloom (6tbs/2Gal) + Grow Big (3tbs/2Gal) + Kanga Roots (1tbs/2Gal), because I didn’t want to f’up too bad.
A slurry mix test from existing FF HF+CN yielded PPM/TDS 195 (they were ready for a drink sooo…).
Starting H2O pH=8.94 (just calibrated) PPM/TDS=145, EC 290.
After mixing the above nutes: pH=6.71 and PPM/TDS=725, EC 1450.
So my starting feeding was PPM=870 - not high in the least.
As I stated above EC is 2X the PPM/TDS - so do I have a 500 Scale pen?
I asked Vivosun support - waiting for a response.
Also, given the nutrient, I suppose I’ll need to do my next watering with some additional nutes.
Anyway…that’s where I am.
Thanks for keeping-up the communications.