Nutrients: Something out of whack here.

[veritas629]

I've got too much or too little of some nutrient in my current grow. I'm on about my 3rd organic soil grow, so still learning. My grow: Indoor tent, 1.2*1.2m, HLG 550 @ 18", 21-27C, around 65% RH, Cootes type soil, and some misc amendments & teas. Bubba Kush and Cheese in week #5 of flower.

Cheese started showing yellow and then brown tips. Pointing downwards. Started at the top, but most levels of the plant are affected now. The Bubba started pointing down and tip discolouration about a week later. A few big leaves at the top of both strains now show some brown spots.

Could this be a nute burn or excess nitrogen? I have used some fish hydrosolate and kelp ferts (Ocean Grown). Maybe I got too enthusiastic? Or would this be a deficiency, like Ca or Mg?

Heaps of buds developing, but I don't want this issue to slow down the bulking up stage!

 

[puggle6]

looks like N tox

 

[afghan bob]

An E.C pen would make it easy 2 get a handle on ure nutes

At least u would know if u over feeding

 

[Hudo]

looks like N tox

I'm with you mate looks like the old nitrogen claw they get it easy during flower they need fuck all nitrogen at this stage give em a good flush and stop adding anything with nitrogen and just use flower fertiliser but wait a couple days after you flush them

 

[itchybro]

hi mate

what size pot are you in
have you checked moisture levels
what's your watering routine & do you get run off when you water

what amendments have you top dressed , not all amendments have nitrogen but most do , to a more or lesser amount
kelp will have a small amount of nitrogen , alfalfa or lucerne will have a larger amount of nitrogen , barley straw will have
zero nitrogen where malted barley will have a little nitrogen , less is always more when it come to individual amendments
top dresses of compost or castings are a good choice because they have NPK but you also get the biology to go with it
of cause a compost made of chicken manure will have a higher level than mushroom compost

you don't want to flush a living soil because it has a different effect to flushing a coco type system
a living soil system is exactly that , biology is constantly converting organic matter into plant available nutrients
in a biologically active system the plant will only take what it needs , too much or not enough water will alter that
biology , i've said it many times water is the cause of alot of misdiagnosed plant problems

 

[Hudo]

hi mate

what size pot are you in
have you checked moisture levels
what's your watering routine & do you get run off when you water

what amendments have you top dressed , not all amendments have nitrogen but most do , to a more or lesser amount
kelp will have a small amount of nitrogen , alfalfa or lucerne will have a larger amount of nitrogen , barley straw will have
zero nitrogen where malted barley will have a little nitrogen , less is always more when it come to individual amendments
top dresses of compost or castings are a good choice because they have NPK but you also get the biology to go with it
of cause a compost made of chicken manure will have a higher level than mushroom compost

you don't want to flush a living soil because it has a different effect to flushing a coco type system
a living soil system is exactly that , biology is constantly converting organic matter into plant available nutrients
in a biologically active system the plant will only take what it needs , too much or not enough water will alter that
biology , i've said it many times water is the cause of alot of misdiagnosed plant problems

Yes To much water is no good but You will want to flush if one of his teas was loaded up with to much nitrogen and it's only started to happen now during flower which is when N Tox raises its ugly head, when the need for nitrogen drops off dramatically.So if he's had the same water schedual all the way through and the symptoms have only showed up in flower for me the finger is pointing at N Tox but without being across everything its a guess if he's added to much nitrogen even if it's a living soil there's only one way out that's get it out or sit back and hope it doesn't effect yield maybe try flush one and then water the other one less that way your learning as you go you can put 2 and 2 together as to what caused it depending on the outcome this grow may suffer but the knowledge you gain will pay you back 10 fold.

 

[veritas629]

It seems the generally consensus is too much nitrogen and that is what I was suspecting. I've added a few nutrient sources that could be the culprits: fish hydrolysate, worm castings, and teas. I probably should have full stopped the fish and worm additions when I flipped to flowering, rather than just slowing down. The teas probably don't add too much, but I'll stop all inputs going forward.

All the plants are in the equivalent of a 200L Earthbox. Flushing the way I've done with hydro is not feasible. I'd end up with a mud pit in the box, giant mess on the tent floor, and probably drowned the plants due to insufficient drainage for a big flush. Instead, I'll water heavier for the next few days and hopefully that dilutes the nitrogen a bit.

I've got about 4wks left. Anything I should add to tie-up, dilute, or rebalance the nutrient ratios? I'm tempted to use water only and not risk compounding the problem with more stuff-ups!

 

[Hudo]

Yeah to big to flush Saw dust or fine woodchips can help absorb some of the excess nitrogen? Not sure how effective it would be without being mixed in I've never grown in somthing to big to flush

 

[Donothing-garden]

It seems the generally consensus is too much nitrogen and that is what I was suspecting. I've added a few nutrient sources that could be the culprits: fish hydrolysate, worm castings, and teas. I probably should have full stopped the fish and worm additions when I flipped to flowering, rather than just slowing down. The teas probably don't add too much, but I'll stop all inputs going forward.

All the plants are in the equivalent of a 200L Earthbox. Flushing the way I've done with hydro is not feasible. I'd end up with a mud pit in the box, giant mess on the tent floor, and probably drowned the plants due to insufficient drainage for a big flush. Instead, I'll water heavier for the next few days and hopefully that dilutes the nitrogen a bit.

I've got about 4wks left. Anything I should add to tie-up, dilute, or rebalance the nutrient ratios? I'm tempted to use water only and not risk compounding the problem with more stuff-ups!

Here's my take on using amino or other N sources with organic soil media: use it when visual signs indicate that it's needed. If your plants look healthy and deep green growing in what you definitely know to be a good soil, just spoon feed topdressing or none at all. Worm castings won't hurt anything at all if properly finished. But yeah, definitely a nutrient toxicity, potentially other than just N.

 

[Donothing-garden]

Here's my take on using amino or other N sources with organic soil media: use it when visual signs indicate that it's needed. If your plants look healthy and deep green growing in what you definitely know to be a good soil, just spoon feed topdressing or none at all. Worm castings won't hurt anything at all if properly finished. But yeah, definitely a nutrient toxicity, potentially other than just N.

Also, if the teas are compost teas, just ditch it and replace with compost extract. Way easier, less risk of breeding pathogens. Just throw a handful of compost in a non chlorinated bucket of water or put the compost into a mesh bag, massage humic acids, biology etc into the water for 30 seconds or so. That biology will multiply in your soil rather than the brew... Easy.

If they are nutrient teas, you are applying lots of nitrogen from the tea, plus N from your hydrolysate, plus N from castings, plus N in soil and solution. Lots of N! It's an easy one to see and quickly correct if running low.

 

[puggle6]

I'm not even close to help rectify this for soil but is molasses (for accelerated breakdown) or Nitrifying bacteria (Aquariums use this) a way to amend this?

@Donothing-garden

 

[veritas629]

Yeah to big to flush Saw dust or fine woodchips can help absorb some of the excess nitrogen? Not sure how effective it would be without being mixed in I've never grown in somthing to big to flush

I've read up on sawdust for soil. It works, but seems to be long term solution for chronically high N soils. I suspect adding some now won't help this grow and may complicate my next grow. While googling sawdust, I saw unactivated Biochar may also reduce nitrogen. But also suck up other important nutes....

 

[veritas629]

Also, if the teas are compost teas, just ditch it and replace with compost extract. Way easier, less risk of breeding pathogens. Just throw a handful of compost in a non chlorinated bucket of water or put the compost into a mesh bag, massage humic acids, biology etc into the water for 30 seconds or so. That biology will multiply in your soil rather than the brew... Easy.

If they are nutrient teas, you are applying lots of nitrogen from the tea, plus N from your hydrolysate, plus N from castings, plus N in soil and solution. Lots of N! It's an easy one to see and quickly correct if running low.

Lots of good info there DG. And clearly I have too many N sources. Next grow I'll start with no NPK and just let those future plants deplete the soil's high nutrient load.

I'm thinking of getting some soil test kits for NPK and pH. I'm hoping if I use them for a few grows too learn about my garden's cycling, I'll get a feel for it and then I can work from some informed experiences.

Anyone used soil test kits before?

 

[Hudo]

I've read up on sawdust for soil. It works, but seems to be long term solution for chronically high N soils. I suspect adding some now won't help this grow and may complicate my next grow. While googling sawdust, I saw unactivated Biochar may also reduce nitrogen. But also suck up other important nutes....

You may just have to chalk this one up as experiance learned and profit from it in future grows

 

[veritas629]

I'm not even close to help rectify this for soil but is molasses (for accelerated breakdown) or Nitrifying bacteria (Aquariums use this) a way to amend this?

@Donothing-garden

I have lots of experience with nitrifying bacteria via aquaculture. I think it would be a mistake in my situation. The bacteria transform ammonia (NH4) to nitrites (NO2) to nitrates (NO3). It might degrade some of my higher order N compounds to more bio available N compounds. More bio available N sounds like adding fuel to my current fire! I'm happy to be corrected if I'm off base here...

 

[puggle6]

I think NO2 is more commonly associated with tox in cannabis (particularly) rather than NO3 but I may be misguided.

Of the 2 bacteria isn't it one that turns ammonia to NO2 and the other NO2 to NO3?

 

[veritas629]

I think NO2 is more commonly associated with tox in cannabis (particularly) rather than NO3 but I may be misguided.

Of the 2 bacteria isn't it one that turns ammonia to NO2 and the other NO2 to NO3?

You could be right about NO2 being more toxic. For aquatic animals most toxic is NH4 > N02 > NO3. There is probably two factors, the compound that is most toxic and the compound that is most bio available. I'll be hitting the vape and researching that tonight!

And yep, you're right about the two bacteria groups... at least in water, maybe soil is different?

 

[itchybro]

when you say 200L earthbox you mean 200L SIP ( sub irrigated planter ) , as far as i know earthboxes don't come in 200L

if your using a SIP are you using a shower cap , aka a plastic mulch cover which will stop evaporation & keep your soil moist
from top to bottom

if your using a wicking system like a SIP you should be using water only in the reservoir & only re fill the res when it's pretty much
empty , without a plastic mulch cover the top will dry & if your then watering from the top your running the risk of over watering
you can water from the top but you'll be walking a very fine line , when you water from the bottom like a SIP the soil can get
quite wet , to the point if you tried to keep the soil that wet via top watering you would def over water , sub irrigation is a completely
different beast

as far as compost teas go i agree with DNG extracts are much better choice & you should avoid NPK bottle feeding as much as poss

 

[afghan bob]

Hey buddy u gotta a guy who breeds and is involved in operating a seedbank offering advice
And a legend of soil workings who has helped us all over yrs
Your off 2 excellent start as far as advice goes
U is a very lucky man.....[woman, goblin, pixie ect]

 

[veritas629]

when you say 200L earthbox you mean 200L SIP ( sub irrigated planter ) , as far as i know earthboxes don't come in 200L

if your using a SIP are you using a shower cap , aka a plastic mulch cover which will stop evaporation & keep your soil moist
from top to bottom

if your using a wicking system like a SIP you should be using water only in the reservoir & only re fill the res when it's pretty much
empty , without a plastic mulch cover the top will dry & if your then watering from the top your running the risk of over watering
you can water from the top but you'll be walking a very fine line , when you water from the bottom like a SIP the soil can get
quite wet , to the point if you tried to keep the soil that wet via top watering you would def over water , sub irrigation is a completely
different beast

as far as compost teas go i agree with DNG extracts are much better choice & you should avoid NPK bottle feeding as much as poss

Hey Itchy, I should be a little more clear about the container/bed. I have a Vegepod, which is similar to a SIP. It is like a SIP in that the soil sits above a water reservoir and the plants can drink from that water. The res acts kinda like a back up and collects excess water during good times and the plants can drink from it during dry times. BUT, it does not have a good way to add water manually. I thought I was a smart fella and put some autopot valves in that SIP res and hooked them to an external res. The idea being that I could walk away for my work trips and the watering was good for a week+. However, one of the valves got stuck open, maybe roots crept into it. Thus I had to cut them off and manually water. Unfortunately, access to the valves would require digging the soil up. I thought about that, but after cleaning 150L of water from the tent twice, I'm not going to use the valves unless I can access them for weekly maintenance.

After this run, I'm considering drilling an access port to add water to the SIP res. At the same time, I'd add a sight-glass so I can monitor the SIP water level. However, the manual water is working pretty well....

I'm going to look into the "shower cap" idea. Is there a risk that with no air circulation & moisture that you could get rot at the main stem's base?