Here are a couple pics from my cabinet grow, they look healthy but they just don’t seem as green as I’d like them to be. I’m feeding just below the recommended schedule from MegaCrop and actually working up to it as the plant mature. Does it look like they are underfed? Or maybe need a little extra cal/mag? There is no burning going on so I’m thinking I’ll just boost the ppm of my nutes and see how it goes. Also since this cabinet is pretty crowded, I think I’ll be flipping it to flower fairly early so I can get the males to reveal themselves and clear it out a bit. That has always been a issue with me growing regular seeds. I don’t have the space to take clone for sexing so I just gotta flip the cabinet and cull.
Well here are some of the yellowing plants…
So based on this paragraph from the Greenleaf site, I will increase my feed and see how it goes.
The Feeding Calculator is used as a general starting point for finding the right amount of nutrients to use. Depending on your setup, you may benefit from using more, or less than the suggestion. A good idea is to keep a close eye on your plants with visual inspection:
1: If the plant is responding very healthy, with good color leaves and growth, then the dosage is fine.
2: If the plant is more pale green color, with lower growth, you could consider increasing the dosage.
3: If the plant is overly dark green, or showing signs of tip burn or tips turned downwards, you can consider to lowering the dose.
Feed that poor girl. 
I’ve been using Mega Crop at near the full 5g per gallon dosage they suggest and my plants look a lot like yours. They were showing Mg def pretty bad at first and maybe N too. Now they are looking a little P def, but that could be because I was giving them so much Mg that I locked it out. I’m not completely sold on the Mega Crop yet.
I’m now giving 22 grams in 5 gallons so maybe that’s still not enough… my ph is good near as I can tell, around 6. I’ll have a new Apera ph meter mid week so I hopefully will be able to more accurately adjust that. My ph is very stable in the coco chips though. It seems that the feeding instruction at their web site are a bit mild…
Coco? I’ll have to check my notes…
That should give you a good point of reference. My tap ppm is usually 70.
I’ve always been told for coco/hydro setups you want your res ph to 5.5 and by the end of th res it’ll have drifted to 5.8-6 which gives your plant an optimum ph swing to pick up as much food as possible
I typically have my coco pH drift the other way when in flower as it acidify’s.
Just made a new batch of megacrop for my bucket reservoir. I was trying it at a heavier 820-840ppm or a 1.65-1.7ec such as i recommended above which is around 5.8g a gallon in comparison to others. But even though the plants were growing great and no issue yet, the feed level for mysetup was just a tad to heavy and i know if i continue at those levels i will potentially run into issues.
Was running at a lower 720ppm or 1.45ec and i know the plants could take more, so currently running a batch between those two point to see if thats my sweet spot
Well I am not sold at all 
I dont use megacrop tho… But in my experiences, if something is missing, except calmag, my plants are still very Green and lower leafes start to go yellow. But these look different. They are all wierd colour. It seems like they Just couldnt eat something at all. Get me? The plant Just grows without some element and thats why its all yellow and not Just some part. I would try different nutrients…
But corect me As I Said I dont have experiences with MegaC…
I am trying something different, megacraop. This is only my first experience with it. So just trying to get the dose right.
Ok, so I changed the res, 5 gallons with 30grams MegaCrop, added 10 ml cal/mag and ph’d to 5.5, 910 ppm according to my meter, my tap starts at 40ppm.
See what happens…
I’m pretty excited to see if this helps!
I’m about to try something similar. Except I’m dropping the Cal/Mag and just going straight MegaCrop at 1.7-2.0 EC. I’m using Coco coir, what is your media? Soil? 5.5 would be a little low for me
Hi Rich, I’m in coco chips. I’m adding cal/mag simple because my tap water is pretty pure and only at 35 or so ppm. The plants seem to be growing well just a little bit of yellowing so I’m trying to find the happy spot. I’m starting at 5.5 hoping for a little rise and swing thru about 6 or so.
When I first put thes plants into the coco chips and for the first week and a half, I was testing the ph with drops into a vial and comparing colors against a chart. I had a couple of cheap pens but could never get them to agree and so didn’t trust either. Anyway, I think I may have been running my ph to low during that time so now I have a new Apera pen that seems pretty accurate so started my ph yesterday at 5.5, today it’s at 5.8 so that’s good and I’ll let it swing up to 6.5 before making any changes. It does look like the newer growth is starting to green up. There are no brown spots or turning edges, just the yellowing of the older leaves. I’m hopeful that this is improving…
Hi @2RedEyes There are many pH buffers on the market which show you the exact pH 
And by that you can tell if your pen measures corectly. I use pH 7 buffer once a week to Check out if my pen still measures accurate It really helps to be more relaxed when you know its calibrated properly.
I am looking forward to see them jumping Back
Good luck
I have good confidence in this pen whereas the other two left me guessing. We will see, thanks!
I bumped the feed mixture up to about 900 ppm and ph’d to 5.6. The ph does not seem to be drifting much so I think next time I’ll start it a little higher around 6.0 and see if that helps but I think they are starting to green up a bit in the new growth. I put in this far red flower initiator as well and I’m gonna flip’m so we can see who’s the girls in the bunch. All ValentineX Crossed with various other high cbd strains…
We see…
Nice, did you build the far-red light yourself? Running it an hour after lights out?
Yes, I built it yesterday so I haven’t tried it yet. The plan is to turn it on for 5 minutes when the main growlight goes out. I have no idea if it works or not so just an experiment. It was cheap enough and I like diy so what the hell…
