A puzzeling question

Darknes01

Well-Known Member
hey all,
I have a situation which i cannot figure out so i am here to maybe get some answers.

I have an RDWC system ( 2 of them ) 4 lights each.
System one has 20 plants under 4 lights and
System two has 24 plants under 4 lights.
Now Yesterday i did a water change and my ppm was 1000 for system 1 and 1030 for system 2.
Today 24hrs later system one is down to 880 ( basically they consumed about 120ppm of nutrients )
and system two is down to 990 ( only consumed 40ppm )
This keeps happening every water change.
What are the odds that a system with 4 extra plants would consume less nutrients ( plants are all healthy and doing amazing )
One difference is my ppm meter, system 1 is using a bluelab and system 2 i have an HMdigital H-100

Here is a video of my plants
 
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Darknes01

Well-Known Member
I'd calibrate and try again. That does sound off.
Bluelab is not able to be calibrated but I can calibrate the hmdigital.
I just find it hard to believe that system 2 is eating so little with having more plants vs system 1.
 

Johiem

Well-Known Member
Are the plants in both systems the same age?
Is using the same meter to test not an option?
Double checked for any blockages?
Kinda running out of ideas.
 

Darknes01

Well-Known Member
Are the plants in both systems the same age?
Is using the same meter to test not an option?
Double checked for any blockages?
Kinda running out of ideas.
Excellent idea, I have not checked for blockages. I will do that today as soon as lights come on. Each meter is kind of attached to it's system so I can take it off but it would be a pain to be honest
 

Wastei

Well-Known Member
Maybe just genetics and/or different stages of growth? Same kind of lights on the reservoirs?

Oh you got your pens/probes attached to the systems?. Hard to tell without the same point of reference then.
 

Darknes01

Well-Known Member
Maybe just genetics and/or different stages of growth? Same kind of lights on the reservoirs?
Plants are all the same, lights are a little different but all are high end LEDs, I have gavitas hlg650r hlg scorpion Diablos
 

Johiem

Well-Known Member
Ok I thought they were pens.
There's an option. Get a cheapie! Less than $20, portable, and if it when it craps out, no big loss. That's just for verification. And my clouded head was thinking Ph, not ppm, when I suggested recalibration. Sorry.
 

Darknes01

Well-Known Member
I have video that I just made for this current grow so you guys can watch it if you want. I just made the video yesterday so it's pretty current.
 

Johiem

Well-Known Member
Good one @Wastei I hadn't thought of R.H./V.P.D. I can see it. If Your humidity is off you're girls can't transpire an efficiently
 

Wastei

Well-Known Member
Plants are all the same, lights are a little different but all are high end LEDs, I have gavitas hlg650r hlg scorpion Diablos
Do they yield the same and look the same? Maybe one of the drivers are failing? You could double check the numbers with a light meter.

Everything plays a part but light intensity, temperature and humidity is probably the most important variables to monitor.
 

Darknes01

Well-Known Member
Do they yield the same and look the same? Maybe one of the drivers are failing? You could double check the numbers with a light meter.

Everything plays a part but light intensity, temperature and humidity is probably the most important variables to monitor.
Good point, I have a par meter and once lights come on I'll check quickly just to make sure
 
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