I believe this is a cal/mag deficiency (in coco), but I'm almost up to 15 mL of cal/mag with little improvement.

[Bantersaurus]

4x 3 gal fabric pots with coco/perlite (80/20), feeding daily with ~4 g/gal Mega Crop, 12 mL/gal cal/mag (Roots Organic brand, I wonder if it's very diluted stuff), and some yucca powder. pH is always beween 5.7 - 6.0, usually 5. 7 or 5.8. You guys think I should let it get closer to 6.0 for better calcium uptake?

I used Roots Organics coco palms, and it's pre-washed/buffered.

I did also notice that this mostly happened on the newest growth, so I moved the lights up, and it seems to have improved. Could be a coincidence and it could be the cal/mag, but not sure. I haven't been giving her cal/mag since the start, only the last ~2 weeks.

Last pic is most recent.







- this is them 2 days ago

 

[Mañ'O'Green]

That looks like way too much Cal-Mag. This will induce a magnesium deficiency. Do a flush and reset with 50 PPMs of Cal-mag and the normal MC. Add in 30 PPM epsom salts, some Mykos or other bennies if you have them.

 

[BII]

Generally, MegaCrop already has enough Ca and Mg that supplementing is not usually needed.

Otherwise, rather than overdose the plants (and risk locking-out other nutes), the next time you think you have a deficiency consider foliar feeding just what is needed. For example, if you suspect Mg deficiency, spray with some MgSO4 (Epsom salt). Foliar feeding acts much quicker and is simpler vs. messing with your feed.

 

[karlkutta]

Generally, MegaCrop already has enough Ca and Mg that supplementing is not usually needed.

Otherwise, rather than overdose the plants (and risk locking-out other nutes), the next time you think you have a deficiency consider foliar feeding just what is needed. For example, if you suspect Mg deficiency, spray with some MgSO4 (Epsom salt). Foliar feeding acts much quicker and is simpler vs. messing with your feed.

I had to add calmag to my grow. Thought I didn't need it with MC but then ran into some serious issues. But 15ml sounds alot. Can OP get ppm and what does it say on the bottle?

I got foxfarm calmag and I think it's 5ml/gallon

 

[BII]

I had to add calmag to my grow. Thought I didn't need it with MC but then ran into some serious issues. But 15ml sounds alot. Can OP get ppm and what does it say on the bottle?

I got foxfarm calmag and I think it's 5ml/gallon

Adding 3x the recommended amount of cal-mag supplement is a pretty radical and risky way to treat what seems to be a minor problem, if it's even a problem at all (with your plants looking good to me). And again, if you really need targeted supplementation, consider foliar feeding, and avoid all the problems with pH, lock-outs, etc.

 

[Bantersaurus]

It was a Roots Organic Cal Mag and the suggested amount was 5 - 15 mL. I guess there was some light bleaching that made me think it was a cal/mag issue. The real issue all along was that my light was hung at the wrong distance.

Should I flush it with 5.8 ph tap water, then resume regular Mega Crop without cal/mag?

Adding 3x the recommended amount of cal-mag supplement is a pretty radical and risky way to treat what seems to be a minor problem, if it's even a problem at all (with your plants looking good to me). And again, if you really need targeted supplementation, consider foliar feeding, and avoid all the problems with pH, lock-outs, etc.

That's not me lol

 

[4d-Rock]

It really depends on the brand of CalMag, I have CaliMagic which is 1-0-0 for npk but it’s super hot.
The recommended dose on the bottle is 1mL/L and that alone is an increase of 300ppm.

 

[Bantersaurus]

It really depends on the brand of CalMag, I have CaliMagic which is 1-0-0 for npk but it’s super hot.
The recommended dose on the bottle is 1mL/L and that alone is an increase of 300ppm.

Roots Organic Cal/mag. But I bought some TPS cal/mag that's more concentrated and seems better overall. Link below.

Amazon product

I dimmed my lights a bit to combat the light bleaching, and I'll stop feeding cal/mag for a bit to see the difference.

 

[Olderfart]

It was a Roots Organic Cal Mag and the suggested amount was 5 - 15 mL. I guess there was some light bleaching that made me think it was a cal/mag issue. The real issue all along was that my light was hung at the wrong distance.

Should I flush it with 5.8 ph tap water, then resume regular Mega Crop without cal/mag?



That's not me lol

If you flush, do it with a ph'ed nute mix of the concentration you intend to leave it with. There is no point adding stress to the plant by hitting it with a lot of plain water at the wrong ph. The change in EC and pH would be extreme, and could set the plant back a notch. If you suspect a problem with what you have been using, mix up lots of nute mix and keep flushing until the runoff is close in pH and EC to the input. It may take a fair bit of nutes, but it will make sure that the plant is left in the state you intend to try out for improvement.

 

[Bantersaurus]

If you flush, do it with a ph'ed nute mix of the concentration you intend to leave it with. There is no point adding stress to the plant by hitting it with a lot of plain water at the wrong ph. The change in EC and pH would be extreme, and could set the plant back a notch. If you suspect a problem with what you have been using, mix up lots of nute mix and keep flushing until the runoff is close in pH and EC to the input. It may take a fair bit of nutes, but it will make sure that the plant is left in the state you intend to try out for improvement.

I came to this conclusion myself. I won't be doing a full flush because I've been watering daily to 10 - 20% runoff already, but I will be taking out the cal/mag I was adding and leaving just 4 g/gal of Mega Crop and some yucca powder for even water distribution (hard to water these suckers!).

On a different topic, should I bother with a PK booster in bloom with Mega Crop?