Hey fellow growers, facts first: - SF 2000 - super soil (followed the guide on "Organic Soil Mix For Beginners" - OG Kush (photos, Nirvana Seeds) - 4 weeks into veg - (tap)water ph'd around 5.75 - runoff is around 6.7 - gave them basic compost tea 2 weeks ago and yesterday - temp/rh are in range Edit: - pot size is 4.5 US Gallon (17 liter) - grow space is roughly 3x3 (80x80cm) I always seem to run into deficiency issues after a few weeks. Leaves start to yellow and in this particular case they even start to develop brown spots and somehow start deforming. Stems of the upper part start to turn purple. Plant is quite flabby/droopy. I always let the soil dry a little between watering (every 3 to 4 days). I can't imagine that there is not enough nutrients available, it somehow feels like the reason for the deficiency is something else. Our tap water is pretty basic with a ph of around 8. Do I need to find another source for water? Do I maybe need to lower ph of the soil? If so, do I just add sulfur or is that a bad idea? Is there a other cause for the problem? I'm still new to growing and at this point it really starts to feel frustrating as I just can't find a solution for the ever occurring yellow leaves. Hope the picture are ok. Any constructive advice is much appreciated Sent from my SM-G973F using Grasscity Forum mobile app
I'm not a soil grower but I do know that you should be watering with a pH around 6.5......your run off is perfect.
I would suggest using rain water. You likely have high bi-carbonates in your tap water with a pH of 8. Also water more often. Living soil likes to stay moist. This article may interest you. https://citrusagents.ifas.ufl.edu/e...al Problem with High Bicarbonates- Morgan.pdf
Looks like Cal deficiency and also makes sense with those lights. Those Samsung LEDs make them use more nutrients, especially CalMag. I had the same issue when I switched to QB style lights. Also makes sense from time frame.
Can you post a photo of the whole plant including the pot? My hunch is yours are too small for the plant size.
I was assuming that I need to calibrate the ph accordingly to the run off as this is what help me estimate the soils ph. When I increase watering ph from 5.7 to 6.5, I end up with a run off of that reads something like 7.4, which is too high afaik. Is this approach wrong? Sent from my SM-G973F using Grasscity Forum mobile app
Interesting read. Thank you. I don't know exactly how much Hydrogencarbonate is present. A data sheet from 2018 shows that carbonate hardness is 13.9°dH without showing the part of each component of this group. Unfortunately I can't collect rain water here at my place but there is a brook just across the street. Not sure if using this water is a good idea. Sent from my SM-G973F using Grasscity Forum mobile app
Fortunately our local public water supplier is testing the water every few years, last measured 2018 with a carbonate hardness of 13.9°dH. I just need to figure out if that is too high or too low. I might post the data sheet here but have been to lazy translating it. Let me know if it would be useful Sent from my SM-G973F using Grasscity Forum mobile app
7 us gallon or 27 liter Sent from my SM-G973F using Grasscity Forum mobile app Edit: Sorry confused what I've been planing with what I actually did. Size us 4.5 US Gallon (17 liter)
Thanks for this tip. Will try and supply more CalMag and also try to find a way of decreasing soil ph due to the assumption of too much bicarbonate as this will neutralizes the bicarbonate if I got it right Sent from my SM-G973F using Grasscity Forum mobile app
Will do once I have my lunch break. Pot size is 7 us gallon Sent from my SM-G973F using Grasscity Forum mobile app Edit: Sorry, been confusing something. Size is 4.5 US Gallon (17 liter). Pic attached (this brown spot on the floor is just compost tea)
Just as reference, these two Cookie autos (Dinafem) are about the same age but look like they are doing well (same tap water, same ph, same compost tea feeding, same super soil) Sent from my SM-G973F using Grasscity Forum mobile app 2x2 Pot size is 3 US Gallon Light is a GC 4 - Greenception | LED Grow Lights
Maybe slightly N deficient, and I think it could use more water. You don't really want to let the soil dry out. Better to water in small amounts more often and keep a steady hydration in the soil. As for pot size, it doesnt look like an issue right now but with a plant that size I think you will run into issues during flower with that 5gallon pot.
Ok, will give her the leftover from the recent compost tea and add some liquid seaweed. Do you have a simple recipe for a DIY CalMag solution? At what ratio do you apply CalMag and how often? Sent from my SM-G973F using Grasscity Forum mobile app
Edited size in after Taoist ask for it. My bad, didn't think about it in the first place. Been a while since last posting here Sent from my SM-G973F using Grasscity Forum mobile app