Spots on leaves (2 diff kinds - same grow)

[umop apisdn]

Hello. I have 4 GSC Thin Mints pheno photos and two of them are showing two different issues... or perhaps they're related and just showing up differently? Two of them are darker green with purple hints here and there. Two of them are lighter green with no purple. All 4 are bagseeds from the same bag.

Problem:

GSC 1: the picture that has the darker leaves with natural purple (circled in white) has similar colored purplish-brownish splotches (circled in red).
GSC 2: the picture that has the one big red circle, same strain, no purple, has some small rust colored dots, surrounded by yellowing.

Medium/grow method: Soil / OF, 1 gallon fabric pots. (it's a small 2x2 tent so i wanted to keep them small)

Feed: and supplements used: GH Flora Trio + Cal-Mag & first dose of Recharge was about 5 days ago.

water source: Tap (hard)

Strain/age: GSC Thin Mints / 50 days

light used: For the first 42 days they were under Viparspectra Par600 & the past week or so have been under the Spider Farmer SF-2000. When I swapped the lights I started it up around 30" and went down to around 24" over a few days. Then got a little worried it was too much so raised it back to 30".

Climate: 50-60% RH @ 68F - 80F

Additional info:

Thanks in advance!

 

[Stooby snacks]

When you say water (tap).Hard water, what does that mean? Whats initial ph, and are you hooked up to the municipal system?
Im suspecting a combo 1-2 punch of chlorine toxicity, and potassium deficiency which will cause magnesium to lock out eventually if not already.

 

[Stooby snacks]

@umop apisdn bazinga!

The second smaller plant is most likely a calcium issue.

 

[umop apisdn]

So the spots that

When you say water (tap).Hard water, what does that mean? Whats initial ph, and are you hooked up to the municipal system?
Im suspecting a combo 1-2 punch of chlorine toxicity, and potassium deficiency which will cause magnesium to lock out eventually if not already.

My tap water is about ph 7.1-7.2 and I am hooked to municipal system (water report linked in original post). I mix nutes, in the correct order now (was doing the cal-mag wrong/after nutes for the first 30 days or so oops), then ph to 6.5 - 6.7 (currently).


Also, here's an update on the first pic... spots are getting much worse now and are no longer the same purplish color, more dark brown/rusty.

 

[umop apisdn]

Oh.... also.... I transplanted all 4 of these plants yesterday into bigger 3 gallon fabric pots, from 1 gallon fab pots and the roots were super hard. not wet, not even many visible aside from some on the bottom (but not as many as i would like to see there). Though it feels like the entire 1 gallon fab pot turned into solid roots! the surface of the soil is hard, i can hardly even press my finger into it and one of them has almost as spherical surface from the roots.

 

[Waira]

Suspect #1-- acidic pH from that OF soil,... it's the most problematic soil I see in here, hands down... this can lock out P especially, and the symptoms match this.... root bound makes matters worse,.... If you've just fed once, then plain lack-of could be part of the problem too....
Get a good soil pH probe, nothing beats in-pot measurements! The Accurate 8 (Control Wizard) is a good unit for this--> hsoil: -- long probe here is the A8....
Now, the catch-22: off pH or lack of, or both... problem is, if it's off pH in there, more feeds can make things worse! So, until the pH is determined, anything you do is a gamble,.... transplanting done now, it's more complicated to deal with; worst case solution is to flush the pots, but maybe you got lucky with the OF crap... Do a slurry test of the bag soil, if you have a well working, calibrated pH meter:
-- 1/2c soil, 3/4 cup RO/Di water (no hardness, this will skew results); let it sit for 1/2hr, then drain off liquid and test the pH... this will give a decent reading of the soil's pH,.... next step hinges off this reading....

 

[umop apisdn]

Suspect #1-- acidic pH from that OF soil,... it's the most problematic soil I see in here, hands down... this can lock out P especially, and the symptoms match this.... root bound makes matters worse,.... If you've just fed once, then plain lack-of could be part of the problem too....
Get a good soil pH probe, nothing beats in-pot measurements! The Accurate 8 (Control Wizard) is a good unit for this--> hsoil: -- long probe here is the A8....
Now, the catch-22: off pH or lack of, or both... problem is, if it's off pH in there, more feeds can make things worse! So, until the pH is determined, anything you do is a gamble,.... transplanting done now, it's more complicated to deal with; worst case solution is to flush the pots, but maybe you got lucky with the OF crap... Do a slurry test of the bag soil, if you have a well working, calibrated pH meter:
-- 1/2c soil, 3/4 cup RO/Di water (no hardness, this will skew results); let it sit for 1/2hr, then drain off liquid and test the pH... this will give a decent reading of the soil's pH,.... next step hinges off this reading....

Thank you! And yeah... I have heard OF sucks now. I would never use it for autos, but I thought it would be fine for photos.. who knows... next time around i'm going to use something else. I need a better soil PH meter, i only have one of those 3-way ones from a cracker jack box. the one with the spots seems to have stayed how it was. the spots got darker, but i think new spots stopped appearing. but these 4 plants are def runts, not sure if it's the 1 gal pot or the environmental issues, soil, etc.. the 1 gal pots don't help much im sure... anyway, thanks for the advice!

 

[Waira]

pH is the same for auto's and photo's, it's all about keeping the nutes in available forms,.. off pH fucks that up!
Are you stateside? Roots Organic original is decent soil, Royal Gold King's Mix is very good... if in CA, look for Sanctuary Soil brand, Victory Mix (milder), Empire Builder (hot for seedlings, so make a center pocket of milder soil, about 1L worth, and sow directly)....