Inflow/Outflow Reading

New grower. 1st time with tent and auto watering system. I mixed my water/fertilizer with a EC of approximately 1,000 and a ph of about 5.5. (Yesterday)

Today I tested my tank and the EC was about 1,175 and a PH about 6.4.

Also tested runoff. EC was about the same and the PH was 5.7.

So confusing. Do these numbers sound right? My girls is 25 days old. Color seems a little light but i honestly have no clue.

Any feedback is welcome.


  • Seed - GG4 Autoflower
  • Medium - Coco + Perlite (Mother Earth)
  • Container - #5 Airpod
  • Fertilizer - Jack 3,2,1 plus silica & epsom salt
  • Sprouted - 2/9/23
  • PH - 5.8 - 6.0
  • EC Inflow - Target 1,000
  • Water/Fertilizer - 3 Times Daily (till runoff)
  • Lighting - 750 PPFD at 24”


  • Tent - 2x4 AC Infinity
  • Exhaust Fan - AC Infinity Cloudline Pro T6 plus controller (always on level 3)
  • Exhaust Filter - To be purchased
  • Oscillating Fans - Two AC Infinity (always on)
  • Light - HLG 350R (18/6)
  • Dehumidifier - Cycles on at 65% humidity
  • Watering System - Halo top feed 3 times a day till runoff
  • Water Tank/Container - 15 gallon
  • Bubbler - In water tank
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EC is little low at 1.0/500 PPMs. Bump that up to 1.8/900. Ph will drift upwards when the nutrient solution is allowed to set stagnant. I use a wave maker to move the water in the res to help with this. Amazon has them and fairly inexpensive. The run off is going to waste correct?:love_you_gesture:


Thank you for the reply.

For clarity, yes my runoff drains to a waste bucket.

I also have a wave maker in addition to my bubbler in the tank.

As far as the EC and your suggestion. You are saying my inflow EC of 1,000 is too low. Your 1.0 has me a little confused. And my runoff number also too low?

New at this so I’m easily confused

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My feed is around 900ppm 5 scale or 1.8 ec from front to back with coco and jacks. With weekly additives though. pH in at 5.8-6.0. Your numbers look fine for the most part.

Is your system feeding to run off each time?


Hi and thanks for the reply

Yes, I water till runoff each time.

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I just noticed @OGIncognito said basically the same thing. Yeah up your PPMs a bit :call_me_hand:t3:


If you just mix the Jacks as directed, ph properly and feed your plants you’ll be fine.

The great thing about Jacks, especially for beginners, is the ease of use. It is the same strength mix from seedling through harvest.

Everyone keeps complicating a very simple process.




You’re reading this wrong Growmie and not sure what TDS pen you have. To simplify things use the PPMs setting if that’s an option and the 500 scale. If you’re using Jacks and as suggested earlier…it’s very simple. My tap water source has a TDS of 70 and a PH of 7.1 and jacks at full strength comes out at 920ish and a PH of 5.8-5.9 :love_you_gesture:


I agree with @OGIncognito tgat you need a wave maker. My PH will drift slightly in my reservoir since the wave maker keeps all the nutes mixed.

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This is what’s confusing folks: EC is expressed differently from ppm 500 and ppm 700 scales. An EC of ‘2.0’ equals 1,000 ppm on the 500 scale. It would be good to clarify what you are actually measuring.

In my experience with Jack’s there is not need to reduce salt levels through flushing as the salts are gentle enough for the plant to handle. I do Autopots with Jack’s and never a problem with salt buildup.

Plants do look hungry IMO.



Thanks for the reply. I do have a wave maker in the tank. It pumps water to the surface and it falls back into the tank. I also have a airstone in the bottom producing lots of bubbles.



I really appreciate the response and attempt to help me. Maybe I have the wrong meter to test EC or PPM?

Pictures below of my meter. Has a PPM mode and another mode that says US/CM.

I have been using the US/CM mode and trying to get a reading of 1,000 - 1,100. There is no indication of a reading of just 1.0 or 2.0 and no indication of a 500 or 700 scale?

So, I know it’s aggravating trying to explain this but I’m still confused.

If…. I’m supposed to use the PPM mode, what target should I go for in my Jacks 321 mix?

Do I have the wrong meter??

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Use the ppm setting and shoot for 900 ppm.

That first setting is EC measured in micro Siemens per centimeter


Use this setting and mix your nutrients at full strength and test the PPMS. Target 900-1000 from veg thru harvest. Soil PH of 6.5 is optimum and 5.8 for coco :love_you_gesture:

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Got it. Thanks

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Keep me tagged Grow Bro, I’ll hang out with you :love_you_gesture:


I’m hoping you’ll mentor me when I get ready to germinate a new seed.

I am failing miserably when it comes to germination. I got one plant out of 10 ILGM GG4 seeds. They were very nice and mailed me 5 replacements.

I’ll continue with this one plant until harvest then ask for step by step help on germination.

I have read, and read, and read article after article and post after post regarding germination. Lots of different methods.

Definitely user error on my part.

I’ll get with you in several weeks when this plant goes to harvest. Hope that’s ok.

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Absolutely Grow Bro. Getting through the seedling period/ first 14 days is the toughest. I have a very simple germination process and have been very successful… there’s always the bad beans that just don’t pop or germ :love_you_gesture:

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