Dialing In MEGA CROP for Auto's

[Kyote]

Is there a consensus on how (or if?) to supplement MegaCrop with CalMag? I just topped off my autopot res with 3g/gal MC and 2.5 ml/Gal CalMag and immediately saw huge mag deficiency issues across all three pots. I gave a epsom salt foliar feed (1 tsp/gal) and they responded well, so I added some dissolved mag to the reservoir. They were at 560 ppm, after seeing their reaction I diluted with the epsom solution to about 470. pH is 5.9-6.1.

I'm growing in mostly coco/perlite with some added Roots Organic soil thrown in (won't be repeating that mistake - next time it's either/or with perlite). I'm seeing massive spotting on light exposed areas of lower leaves on my CDLC plant, with yellowing across nodes on my Zama Express and now Double Grape.

Any tips for baselining my nute rate? 3g/gal MC seems OK but I'm fucking up the calmag somehow. I got advised to add cal in another thread for my Zamaldelica Express, but in another thread I saw someone mention getting good results with 3g/gal MC, 3ml/gal CalMag and .25 g/gal epsom. Any and all insight is appreciated! My girls are hurting right now while I try to get this sorted.

Have you watched this? Common nutrient deficiencies

 

[BII]

Depending on the version, MegaCrop should have all or most of the Ca and Mg the plants need. When I perceive a need, I add ≤1 mL/L CALiMAGic.

By my standards, at that age 3 g/gal MC is low. I'd likely be feeding at closer to 5 g/gal (what does the company recommend?). Boosting the base nutes that much may well take care of any current deficiencies.

Be careful not to add too much Ca or Mg, which can lock-out other nutrients. If you think you have a Ca or Mg deficiency, it's probably best to treat this and with immediate impact by foliar feeding vs. adding more to the medium/soil.

 

[Examiner]

I'm seeing massive spotting on light exposed areas of lower leaves on my CDLC plant, with yellowing across nodes on my Zama Express and now Double Grape.

Same here for the 2nd grow in a row. I've got 4 Double Grapes in a 4x4, Rockwool top drip. I'm about 50 days in so flowering pretty good. V3.0 MC. RO water, I add 75ppm or so of calmag, 400 ppm MC, another 75-100ppm Bud Explosion. Ph 5.6 at low end, drifts up to 5.9 or so before I adjust. My plants flourish through veg and first couple weeks of flower then I start seeing same symptoms as you, and really only in the areas of my plants that receive more light.

Lighting is 2x 240 QB's and I'm dimming them down to about 150 watts each to avoid killing my girls. They are about 15" from top of plants. My gut tells me it's the LEDs but then I read of people running them full blast. What kind of lights you running?

 

[terp182]

Mars SP-3000 limited to 75% until I correct this issue. Thanks for the additions info. I’ve heard a few people say to just stick with straight MC and avoid the calmag, so I’m still scratching my head. Glad to hear it’s not just me, though. I’m ready to change nutes at this point if I can’t find a good model for this.

 

[BII]

Mars SP-3000 limited to 75% until I correct this issue. Thanks for the additions info. I’ve heard a few people say to just stick with straight MC and avoid the calmag, so I’m still scratching my head. Glad to hear it’s not just me, though. I’m ready to change nutes at this point if I can’t find a good model for this.

Sometimes, particularly if you can't determine the problem/cause, it can be best with plants to do nothing. Maybe just continue on with your feeding regimen, and presume MegaCrop (at the appropriate strength; perhaps with some cal-mag supplement) will fix any actual deficiency problem going forward (presuming pH and other environmental conditions are OK).

 

[4d-Rock]

You guys aren’t the only ones with this problem, for me I always have issues during or shortly after the transition to flower.
Here’s my current tent at day 36.

The two Sweet Nurse on the outsides aren’t doing too bad colour wise, seem reasonably healthy, but the Red Poison in the center grew quicker and seems to be starting to see some deficiency or lockout.

They are in fabric pots in Promix HP, I tested all the ph with a soil probe and the Sweet Nurse’s were in range from 5.8 - 6. The Red poison was around 5.4-5.6, so I’m wondering if it has to do with too low pH.
Been feeding every watering at 3g/gal with occasional Sweet Candy, epsom, and CaliMagic, not all at the same time though.
I’m going to try a moderate feed next with a slightly higher pH, maybe 6.2 or 6.3 to try to bring it up a bit.

 

[terp182]

Depending on the version, MegaCrop should have all or most of the Ca and Mg the plants need. When I perceive a need, I add ≤1 mL/L CALiMAGic.

By my standards, at that age 3 g/gal MC is low. I'd likely be feeding at closer to 5 g/gal (what does the company recommend?). Boosting the base nutes that much may well take care of any current deficiencies.

Be careful not to add too much Ca or Mg, which can lock-out other nutrients. If you think you have a Ca or Mg deficiency, it's probably best to treat this and with immediate impact by foliar feeding vs. adding more to the medium/soil.

This really sounds like what's going on, if too much Ca or Mg can lock shit out within normal pH. It's the start of flower and I was worried too high a ppm was affecting the plants poorly, but 560 ppm is lower than they recommend for first week of flowering, which is the 5g/gal (695 ppm/1.39 EC) you recommended.

Mega Crop 1 Part Calculator

Visit the post for more.

greenleafnutrients.com

So tomorrow, I'm flushing out the 2 gallons left in the res and putting in 5 gal of 5g/gal MC only. I'm also foliar spraying with epsom salts one more time at lights out. If I notice any cal or mag issues, I'll add 1 mL/gal of CalMag, or possibly just epsom salts, to the res. I'll update this and my grow thread with progress. Really appreciate the feedback!

 

[Examiner]

Here’s what mine are doing, the yellowing is happening only on the side in the middle where the plant is getting hit by both lights. Both lights are dimmed to about 60%, so 300w total in my 4x4 per my kilowatt meter.
I know plant is bushy AF, going natural this grow. And yes some leaf curling but that’s only 600ppm

 

[pop22]

If it's just on one side, it's light burn

Here’s what mine are doing, the yellowing is happening only on the side in the middle where the plant is getting hit by both lights. Both lights are dimmed to about 60%, so 300w total in my 4x4 per my kilowatt meter.
I know plant is bushy AF, going natural this grow. And yes some leaf curling but that’s only 600ppm

 

[Examiner]

I assume so too, but geez I’m dialing down to about 20w sq/ft at 15” or so. These QBs are another beast (only 2nd run with them). I’m about ready to re-hang the hps... thx for the comment, appreciate it.