Issues with Samsquanch OG. Can't seem to figure it out and it's driving me crazy. Please help me.

[BalzarDanglin]

This Samsquanch OG is killing me!

About 3-4 weeks ago I turned up the light too high and scorched/stressed this plant. I've since raised the light as high as it goes and brought the light intensity down to around 16 DLI, increasing it slowly to around 22-23 as of today. The QB is sitting about 28 inches from the top of the canopy, and is set to around 40% strength on the dimmer.

I overfed (imo) and caused some tip discoloration about 2 weeks ago. Since then I've flushed it with less than 1/4 strength nutes, but the issues are getting worse. I'm now wondering if the poor girl is now hungry. I let the pot dry right out before watering.

I'm in the typical "what is going wrong" spriral. Is it nute lockout, N deficiency, overfed, underfed, calmag deficiency, P or K...I'm at a loss.

Buds seem to be developing well, but the discoloration is really bugging me.

I've included a picture of the poor girl's roommate, who seems to be doing pretty decently in comparison.

Grow details
Strain: Samsquanch OG
Age: 43 days from sprout
Medium: Soil - 2/3 Biobizz Light Mix; bottom 1/3 All Mix
Lights: Kingbrite 240W QB (white/red) 3500k
Environment details: 2.3x2.3x5ft tent, daytime temp 74-76; lights off temp 68-71; RH 48-52 (can go lower but have been slowly bringing it down through the start of flowering)
Nutrients: Biobizz Grow (none as of last two waterings), Bloom (approx 1ml/L), Topmax (1ml/L), Calmag (0.5ml/L). I just ordered some Algamic too.
Watering schedule: Wait until dry, then water around 2L over 5 minutes or so
Air movement: Inline exhaust fan on controller, small oscillating fan, small circulation fan
Ph: Using strips water is between 6-7, Ph pen delivered tomorrow


Thank you in advance for any help.

 

[Bill.de.Cat]

One of the guru's should be able to give you an idea what might be the problem. Got same thing going on in my tent with 2 strains with different nute requirements.

 

[BalzarDanglin]

Thanks Bill.de.Cat

Hoping someone can give me some guidance as I'm at a complete loss as to what to try next. Got my pH pen today and PH is a shade under 7, so I should definitely work on bringing that down (despite being in organic soil + organic nutes).

Light intensity is now around 344 ppfd on a 20/4 cycle, with the lights jacked up as high as I can get them. While I'm sure I burned them a few weeks back (when I relied on a less than stellar app calculation for DLI and got it up to 36) I am hoping how I have it setup now is going to lead to less likely burns. I want to make sure I'm not starving them of light or food unnecessarily. At this stage I'm almost certain it's underfeeding that's causing things to be as they were.

On the flip side, the other girl (CDLC x 3BOG bx to CDLC mix) is doing great and starting to get some nice colour.

 

[BalzarDanglin]

I just pulled up the water test results for my address. This is making me think the issue might lay more towards Mg..


I thought I'd read that Ca:Mg is usually around a 2:1 to 4:1 ration. This is far higher. I've been using Calmag as I know the total hardness was quite soft, but I wonder if dosing with epsom salts might be of use.

Calcium Hardness (mg/l)	11.2
Magnesium (mg/l)	0.6
Potassium (mg/l)	0.3
Calcium (mg/l)	10.2
Total Hardness (mg CaCO3/l)	27.9