Hi folks — Second grow took a tough turn about a month ago. This grow is 68 days in.
Details:
Lazy Lightning in 7 gallon grassroots pots
Kis Organics Bio-char soil (water only)
VPD 1.2 to 1.3
PPFD just under 600
CO2 at 1000ppm
Water was city (209 TDS, 446 µs/cm) but switched to well recently (200 TDS, 293 µs/cm), using RV filter. Note, problems started before the switch.
Watering had been every other day, to keep things moist, typically 44oz, and the occasional 64oz watering, always at 6.4 or 6.5 pH. A few weeks ago I started letting the soil dry out a bit, watering on the 1st day, and then again on the 4th day.
Slurry test recently came back over 8 pH. Last two waterings have been 6.2, guessing that a few extended dry backs killed the microbes.
“Fed” Recharge 2x in the last weeks to up the microbial life
I have only watered to runoff ONCE, and it was no more than a couple ounces in the tray. I’m under the impression super soil shouldn’t be watered to runoff, anyway.
At this point I’m just embarrassed. I keep throwing money at this grow, and I can’t seem to get the basics down. I removed my scrog net, because i don’t want to further complicate things. I bought an Irrometer, and I’m trying to let that guide my watering (hoping to stay around 10 cbar).
Please help me save this grow. I feel like such an idiot.
A closer pic of the leaves would help, what I see is an apparent Magnesium deficiency, maybe because of the soil pH being too alkaline, post those pics in a higher resolution and we’ll see …
Those plants are locked the hell out. Slurry test coming in at 8 is pretty much what those roots are sitting in. I know it’s a water only soil but something in it is driving the pH way to high, u need to flush it out big time. Biochar/ash is known to drive it up and likely what’s causing it and the high pH is killing ur microbes in it
If it were me I’d do a deep flush and immediately hit it with a compost tea doing root drench and foliar spray so they can get some immediate nutrition without risk of burn and start to restore a healthy microbe population
Sorry about your troubles my friend.
I’m no expert or anything like some growers on here but I do use Gaia green mixed with promix to make my own super soil. So I have a bit of experience with super soil. I try not to water to runoff if possible. In flower I use blumats so I don’t have to hand water and they work pretty well at keeping the proper moisture level
I would think about top dressing with dolomite lime to help buffer the ph closer to 7, also possible some Epson salts to help with a possible mag deficiency. I was wrong this is only a solution if your soil ph is too low
They also look a bit droopy, possibly overwatered?
Lime is gonna shoot ph up, if he is already hitting 8 then how high u trying to have him go bro?
Needs to be stuff like coffee grounds or sulphur that can shoot it back down trying to bandaid with a top dress but long term don’t think bandaids are the fix
Promix is 90% peat, peat can swing down all the way to 5 so it’s not surprising ur regimen includes lime cuz that’s what’s getting u to the desired 6.2-6.5
I’m under the impression dolomite lime buffers soil to a ph level of 7, whether it be up or down. Maybe I’m wrong.
Ok yep i was wrong, just for low ph soils like my peat based.
Lime is alkaline and will drive it up, sulphur and coffee grounds are acidic. My first grow I was on the opposite end dumping way to much sulphur in my mix and had my pH all the way down to 5.2, expensive autoflower seeds too off seed supreme. Lesson learned and got way more of a soil biology understanding now for full soil organics
I once had PH problems that got outta hand. I was trying different stuff but turns out my meter was crap and no longer calibrated. If you’re dealing with PH start with your meter. The only way to make sure is to calibrate the meter again and test it against the calibration solution.
Another thought, could this recharge be affecting your PH? Are you checking Ph before or after adding recharge? Just different ideas to look at.
Personally, if the PH meter is correct I’d use a little sulfur, gonna catch hell flushing a organic soil mix. And the flush would stress the plant more for the water it would take to flush
I gotta disagree. Whatever is present in the soil is what’s causing the issue, to throw more stuff in there without blasting out the old typically Is just gonna drive the crazy train to more issues
Pretty interested in following how this gets fixed.
High pH means you’ve got a ton of cations, probably K, Ca, and Mg. Does high pH lock out Mg? Everything I have read implies you see Mg deficiency on the acidic side, not the basic one. Although, excess K can cause micronutrient deficiencies (Ca, Mg, Zn, Fe).
Everything else the plant needs starts getting problematic though, especially at 8. Mn, B especially and let’s not forget P.
I wonder if it’s not Mn or Zn deficiency, mixed with some K excess caused by pH. The question is, how did it get that high?
Probably wouldn’t hurt to email Kis Organics and see if they have any advice.
You’re waiting too long to flip to flower, roots running out of space.
As above so below.
Flip when the plants are about the same height as the pot or earlier and you’ll be good.
Topdressing with fresh organic mulch like grass clippings, kitchenscraps, nettle, dandelion, etc will help them get through flower. Diversity in mulch being key.
Up potting them might be a good idea too.
And stay away from bio char I suppose, I think it’s a bit silly to be burning shit when it’s not necessary. Plants will do fine without.
Well biochar and fireplace ash is extremely alkaline and is one of the shown ingredients, I think it needs to be flushed out that medium cuz it’s creating to high of a pH. Then tackling right behind it a nice castings and other goodies tea is gonna let that plant feed it’s hunger it’s clearly been craving for about the last 3 weeks if I had to guess
The person above answered pretty darn well. It’s not the biochar and I also thought the biochar process actually helps capture carbon from agricultural and whatnot waste.
So, a game-plan could be flush with a couple gallons of plain, 6.5 water. Then add a half gallon of compost tea, followed by a foliar of something…? I have some Roots products on-hand, so I could use Extreme Serene (.25, 0.1, 2). My local grow store has just about everything, too.
