Nutrient uptake rates for NPKCaMgS--a nice graph
- Thread starter HydroLynx
- Start date
rkymtnman
Well-Known Member
wow, lots of info. thanks
are you familiar with Fatman? he's been on and eventually banned from just about every weed forum. i read some of his nute advice and he says that the optimal NPK for bloom is 3-1-4 which is pretty close to what your data shows.
HydroLynx
Well-Known Member
Yes I have been looking at old shcool threads the past few years, link me with some gems if you have...
I tend to look at ppm's of npk etc, like I calculate how much salt is in my res in terms of ppm, but seeing how much other people use is a great start and saves so much time experimenting. I just hope they dont give nkp ratios in terms of P2O5 and K2O as it changes things a bit, unless stated as such
I tend to look at ppm's of npk etc, like I calculate how much salt is in my res in terms of ppm, but seeing how much other people use is a great start and saves so much time experimenting. I just hope they dont give nkp ratios in terms of P2O5 and K2O as it changes things a bit, unless stated as such
rkymtnman
Well-Known Member
i'll look thru my bookmarks and see if i can find anything.
but Fatman's main thing ( i think he did it in elemental PPM, slightly different than label NPK like you said) was 3-1-2 for veg and then bump up the K to 4 for bloom or 3-1-4.
i do know that dyna gro foliage pro 9-3-6 ( i think) is kick ass for veg. so his 3-1-2 is pretty accurate at least from what iv'e seen
HydroLynx
Well-Known Member
Yeah those number are familiar and what I tennnd to target. Am using a 2-1-2 NPK ppm for veg and 2-1.5-3 for flower maybe I'll push it to 2-1.5-4 in late bloom. Still experimenting for DFT hydro. I want to watch what the leaves do, no burn ect. Normally my plants dont complain much but Im growing exodus cheese which is a VERY light feeder, also a good cash strain where I live. Anyways, I've been finding that a stupidly low EC in my hydro system works wonders, like ec-300 seems to be optimal
rkymtnman
Well-Known Member
i like a low EC too. i'm at high elevation so plants just don't grow as fast here.
i do one feed a day at 0.7EC with 0.2 of that well water. so i'm close to you.
i was always a big Lucas fan but those numbers are only 1-1-2. i've been experimenting with different nutes and different ratios latlely.
i do one feed a day at 0.7EC with 0.2 of that well water. so i'm close to you.
i was always a big Lucas fan but those numbers are only 1-1-2. i've been experimenting with different nutes and different ratios latlely.
HydroLynx
Well-Known Member
Same. Well at sea-level. BUT where live and years ago, Lucas used to be 1ml/l micro and 2ml/l bloom which gave like 2-1-2 in veg and 2-1-4 in bloom. Always had leaf burn but the bud was dank. So lately I've trying to replicate more like backward engineer the Lucas ppms from ghe labels and comparing it with grow data like advanced nutes above too see what is optimal according to theory. Other data is scarce tho, haven't found really.
CaliWorthington
Well-Known Member
Thanks for this chart. My takeaways from it are:
1) You don't need all that extra P from bloom boosters
2) Week 4-5 is the only time higher levels of N and K may be necessary
3) Don't cut N in your base until week 5, unless you're mixing fresh nutes every other day. That's the only way you could account for that dip and rise in weeks 3 and 4.
Assuming you're feeding enough, this simplifies the process. Just run steady base nutes, and either up your base a bit, or cut it some and add a high K booster in weeks 4-5 only. The green line says cut down on the cal mag in week 1, and again in week 4.
1) You don't need all that extra P from bloom boosters
2) Week 4-5 is the only time higher levels of N and K may be necessary
3) Don't cut N in your base until week 5, unless you're mixing fresh nutes every other day. That's the only way you could account for that dip and rise in weeks 3 and 4.
Assuming you're feeding enough, this simplifies the process. Just run steady base nutes, and either up your base a bit, or cut it some and add a high K booster in weeks 4-5 only. The green line says cut down on the cal mag in week 1, and again in week 4.
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Even reading through this thread I don't know who's talking P and K, and who's talking P2O5 and K2O.
Kassiopeija
Well-Known Member
I would assume it's in the same form as when it's in the bottle, as e.g. a bottle will contain P2o5 but state "NPK" similarily...
Very interesting document. I wonder if the Ca-development (constantly down) is due to the ever-increasing K? Also they are near a Ca:Mg ratio of 2:1 at the end of flower, I wonder what Cannabis needs excessive Mg for that late in development?
Ca is actually needed in any cell as it's contained in cellwalls but is an element that has difficulty to enter the flowering/fruiting complex as it's heavily separated between apoplastic & symplastic fluid pathways. This is exactly why there are special Ca-enhancing blossomg nute on the market to do away with this weakness... esp. in the case of a plant that has a known problem with fungi in late flower.
And that is known to metabolize Silica rather weakly.
It would've been also important to know what they've fed the sample plants. Because their nutritient profile may have had an influence on the results.
They also seems to have fed their plants Na - which is a non-essential and not beneficial for Cannabis - so it only creates problems.
And they forgot to sample the essential Cl...
I meant in this thread, I wasn't sure who was referring to P, versus P2O5, as someone pointed to. Haha. Just to be clear
Not sure if that's what you meant.
Thanks.
BOWLDOG
Member
Thank you for this document very interesting. You seem to interpret it as a nutrient guide . For me there is a lack of information to do so.
I would like to know how you understand every parts of this document.
The first part with green and red graphics , i dont know if they are analysis results of plant tissues or nutrient solution analysis or just a reminder of the nutrient schedule they give to different plants.
Page 5 we can read its a plant tissue analysis,
With different results on different plants i understand they are studying the differences in nutrients Uptake ?
Well this document is very interesting i would like to know how you used these analysis to make a nutrient program.
I would like to know how you understand every parts of this document.
The first part with green and red graphics , i dont know if they are analysis results of plant tissues or nutrient solution analysis or just a reminder of the nutrient schedule they give to different plants.
Page 5 we can read its a plant tissue analysis,
With different results on different plants i understand they are studying the differences in nutrients Uptake ?
Well this document is very interesting i would like to know how you used these analysis to make a nutrient program.
HydroLynx
Well-Known Member
My plants seem to like 80% Ca-N ratio best, I find myself hovering around 40-50ppm of Ca. Whether more or less is better still eludes me.
I saw on one of the millions of nute threads that K:Ca:Mg should always be supplied at a 3:2:1 ratio in terms of ppm. He was talking in the context of coco but it works well for DWC at about half those concentratios whilst maintaining the same ratio. Cant find it now but those numbers I wrote down.I find that plants seem to love this ratio and bumping up the K to 4:2:1 for bloom. That thread also said something like 100-50-150-100-50 N-P-K-Ca-Mg ppms is spot on. P can go higher, but should be maintained at a 1:2 ratio with Calcium apparently from another source, perhaps even in bloom although the plant doesn't "use it" it still must be there.
I suspect that the ion channels in the root cells that ferry say Ca across, also ferry other Cations like K and Mg across too, and the ratio between them must stay fixed because each cation has a unique affinity for being taken up. K gets sucked up a lot easier than say Mg and esp Ca. Also Ca must be at a higher ratio then to compete with all the K being taken up. That's why hydroponic reserviouirs will deplete K faster than Ca and Mg. So designing the nutes with the graph above together with information on the various uptake rates makes sence. Eg I'd add like 25% more N, P and K than Ca Mg and S because in a few days eg the P and K will be at optimum, and you still have a few days of healthy P and K levels before they disspear into the plant. Manicbotanix.com has a great blog explaining this and he cites sources too. One can also go down the google scholar rabbit hole and read scientific papers but they all concern vegetables and herbs not mj--but there is an argument that all dichots have a similar enough NPKCaMgS ratio. Id love to do my PhD in MJ DWC nutrition if I can find a uni that would let me haha
I saw on one of the millions of nute threads that K:Ca:Mg should always be supplied at a 3:2:1 ratio in terms of ppm. He was talking in the context of coco but it works well for DWC at about half those concentratios whilst maintaining the same ratio. Cant find it now but those numbers I wrote down.I find that plants seem to love this ratio and bumping up the K to 4:2:1 for bloom. That thread also said something like 100-50-150-100-50 N-P-K-Ca-Mg ppms is spot on. P can go higher, but should be maintained at a 1:2 ratio with Calcium apparently from another source, perhaps even in bloom although the plant doesn't "use it" it still must be there.
I suspect that the ion channels in the root cells that ferry say Ca across, also ferry other Cations like K and Mg across too, and the ratio between them must stay fixed because each cation has a unique affinity for being taken up. K gets sucked up a lot easier than say Mg and esp Ca. Also Ca must be at a higher ratio then to compete with all the K being taken up. That's why hydroponic reserviouirs will deplete K faster than Ca and Mg. So designing the nutes with the graph above together with information on the various uptake rates makes sence. Eg I'd add like 25% more N, P and K than Ca Mg and S because in a few days eg the P and K will be at optimum, and you still have a few days of healthy P and K levels before they disspear into the plant. Manicbotanix.com has a great blog explaining this and he cites sources too. One can also go down the google scholar rabbit hole and read scientific papers but they all concern vegetables and herbs not mj--but there is an argument that all dichots have a similar enough NPKCaMgS ratio. Id love to do my PhD in MJ DWC nutrition if I can find a uni that would let me haha
CaliWorthington
Well-Known Member
I had good results trying to follow this chart. I cut cal mag by 25% in week 4 to cut calcium, while adding Sweet Raw to kick up the magnesium. It seems to work, some of my strains are running their best ever. That may also be because I'm refining my bloom booster regimen.
crankdoctor
Active Member
I try to never go over 400 unless I over shoot a bit. But you’re absolutely right on low ec. Going with 0 ec water I’ve burnt tips at 400 with light feeders in top of veg. In Rdwc.