Hi y'all. I'm on day 24 of my first grow; a pair of "Super Hero" Auto fems from Ethos. These little girls germinated very quickly and outgrew their seedling bags and were transplanted into their 1gal fabric pots by day 19. I'm growing in a Vivosun 2x4x5 tent with two Mars Hydro T600 LEDs though only one is turned on right now. Here's a summary of my grow conditions:
Media: Coco (some cheap ass brick I buffered before use)
Relative humidity: 65%
Temperature: 75-80F
Humboldt's Secret nutrient line:
CalMag (5mL), A & B (5mL ea), Golden Tree (1mL)
Input EC (week 3): 400-410uS
Input pH: 5.8 - 6.2
Output EC: +/- 15uS of input
Output pH: 6.7 - 6.8
Light: Mars Hydro T600 @ 36"
Fans: 1 extraction + 2 circulating
At day 24, my plants are still small and very pale. My plant height is a mere 2 and 2.5". Below is a brief timeline of their progress thus far: I'm only showing one of them, but they're practically identical in paleness:
I should've mentioned that I'm using RO water and am "feeding" till 20+ % runoff.
CalMag (5mL), A & B (5mL ea), Golden Tree (1mL)
How much per litre are you giving the plant mate?
I see your pH is rising in the medium too, can you let us know the EC in number like 1.0 /1.2. I think you're measuring the ppm there and EC is a better method 
Its nothing serious though man, dont panic, its easily fixable once we know what's going into the medium
"Keep away from people who try to belittle your ambitions. Small people always do that, but the really great make you feel that you, too, can become great.”
― Mark Twain
Right, I should've mentioned those amounts are what I'm adding per gallon (3.8L), my bad. The EC measurements I gave are in microsiemens instead of millisiemens. So that janky coco I bought... After buffering it, I tested the runoff pH & EC. The EC was fine (.08) , but the pH was 7.8 or so. I must've ran 6 or 7 gal of RO water @ 5.8 pH through that 1gal pot to try and drive the pH down, but it barely budged after each attempt. That bothered me but a few websites I visited said not to follow the runoff pH, so I let it go, although, I did buy some premium coco the following week, so that's on standby for my next grow. 😉
@playdoh yes bro run off ph is pointless mate we control what goes in , she spits out whatever and its that EC number we are after in coco 
sugar had to come back lol , When buffering your coco before use , the ph then is a good indicator we really need that in the sweet spot , I cheat to achieve this as it can be a tricky , and as in cheat il Ph the first soak 5.8 , wash the media , then soak again in calmag water ph 5.8 , she usually comes out , a tad above ph 6 , but watering 5.7-5.8 so its all sweet , pre buffering really does pay off
@woolieback, I'm doing the same process with hydroton in RWDC. Stabilize the PH and pretreat with cal/mag. No bodies complaining.
So it sounds like I planted the seedlings in a sort of "hot pot". The INITIAL pH should be in that sweet spot, like you mentioned. That makes a lot of sense. I will keep fertilizing in the .4 range with my pH between 5.8 and 6.3 and I'll make sure the pH of the new coco is stable when I pot up into their final containers. This seem well and good?
@playdoh not the end of the world bro , last grow i used out the bag out of trust in the brand , too hot but the plant will adapt
@woolieback Right on. I'll keep on with what I'm doing then. Hey, thank you for taking the time to impart some wisdom on me, brother. Thanks to all who chipped in, I do appreciate y'all. I will post some more pics soon. Much love. 😘
Yep, life is coming back to them. 
Two weeks later. Again, thank you all for your advice; I can't say it enough. I should mention I did switch from Humboldt's to GH Flora since it's easier to manage the correct dosage. Hardly any posts on the web regarding Humboldt's.
Our forum is free to join. We are an international cannabis forum that helps people all over the world grow their own personal supply of cannabis. Through our site you will find cannabis breeding forums, cannabis deficiency forums, indoor cannabis growing forums, and much more.
We are a home growers cannabis forum, and we only allow people who grow cannabis for personal use to be members. Our mission is to help you grow your own cannabis. We do not buy/sell/trade cannabis, or equipment for growing cannabis. Our site is strictly a cannabis smokers forum, cannabis growers forum and forum for medical cannabis users.
Use our guides on how to grow cannabis, cannabis grow diaries, and growers forum to find all the info you need to learn how to grow your own cannabis.
Any member who is suspected of growing cannabis for commercial gains will be banned immediately.
Please read our forum rules, and enjoy the site.
Find us on all social networks! Just search for Percys Grow Room