First Hydro Setup - Need help with diagnosing growth stumpage

Okay, first… hey everyone, I will start with the “Support Ticket”.

Strain; Narcotherapy (auto), or Genetics= White widow X, Afgahn Kush & Rudelaris.
Type: “Mainly Indica” (from
Hydroponic, System type: drip and bubble (see pics.) drip added.

PH of runoff or solution in reservoir: 6.2 - 7.0 max

What is strength of nutrient mix: started germination with PPM 260 tap water (sat for several days first) added GH Flora grow 7- 4 -10, brought PPM up to 560.

Indoor, Light system, size: 125 watt CFL, just added 300 watt LED (red/blue for entire grow cycle) might add another when ready for Bloom.

Temps; Day, Night: started from germination to first few leaves area was 75-83 degrees., then added AC now 70 to 75 max.

Humidity; Day, Night: 35% to 65% mostly 50%

Ventilation system; No, central AC with ducting to grow area and carbon filter for later in bloom.

No De-humidifier,

Co2; Yes

I started with pretty good germination in rock wool and tap water, and as soon as I saw leaves I buried the RW cubes in the ceramic balls, (just the tops showing). I was worried about the “water culture” system water level being to low, so I added a 5 gallon external reservoir and drip tubes with a pump. I then mixed up tap water and Nutrient (550PPM), but the after a few days the leaves on the five “Narcotherapy” plants just seemed to stop growing. (the other three plants in the pics are free seeds, but they are doing better that the expensive seeds. Still overall, these plants are three weeks old and not getting much bigger, while my $$ seeds look doomed. Please can someone take a look at the pics and help. I was thinking maybe I shocked them with to much nuts, or maybe the light is not strong enough… I am panicking here . I reduced the NUTS and used 002 PPM water from ZEROWATER pitcher, now with NUTS = 280 PPM.

Please help…


No pics here?? How do you put pics on here??

Your pH is way to high for hydroponics, it should be 5.8, or at least much closer to it most of the time.


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Thanks Macgyver, I have been bringing it down gradually. Do the pics look like that might be the cause the cause???

Most likely. much of your nutrients become unavailable much higher than 6.2 in hydro.

Also be careful of low dissolved oxygen levels in hydro, especially DWC where a large amount of the root mass might be entirely submerged. The reservoir needs to stay near 70f if at all possible. Much higher than 72-73F and you start having some problems, you can maybe get away with higher temps, maybe as high as 78*f in the reservoir if a ton of aeration is used.


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Yeah, but that seedling in rockwool is not suffering from lack of Oxygen, because the rockwool breathes. And at that stage the clear plastic is not doing any harm to the roots.

Good point for future readers though. Keep light off your roots. Allowing light to roots is promoting algae growth.

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