5x5 LED - T-Time grow time

wietefras said:

So how is this relevant? is no relation between the two. At night they barely take up water at all. So yes then they will relatively take up more nutrients than water with lights out, but that's a tiny amount to of their total nutrient intake. My plants drink 6 liters of water per m2 during the day and 500ml during the night. The drop in EC overnight is not easy to measure since it's so small.

Plants do take up more nutrients when they get a lot of light then when they get a bit of light. That's where the big difference is and it's easily quantifiable with a regular EC meter.

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It's very relevant if you actually read it. Do you see all those nutrient uptake charts? Nocturnal nutrient uptake is not that far behind diurnal uptake, while water uptake is far less, meaning your plants can actually handle a higher EC during the dark period as there is less transpiration.

If you are measuring your EC after 12 hours dark during flowering and only seeing a very small drop compared to daytime consumption, then who am I to argue? Likewise if you are lowering EC after switching to 12/12 and seeing what you believe to be better results. But there are probably millions of indoor growers out there following the directions on their nutrient labels that have been formulated by nutrient companies over many years and still getting good results, so either you're an anomaly, or you're just way ahead of the curve. Or perhaps it doesn't make any difference . . .

Personally, I don't subscribe to the theory that 50% more light (18/6 vs 12/12) means 50% more nutrient uptake. But that's just me, and for reasons already outlined.

What I can tell you from experience is that I don't water during the dark, and that effectively raises the nutrient concentration in my pots as they dry out over a 15-hour period (3 hours before lights-off) until the next watering at lights-on.

There is a school of thought that you should water during the lights-off period, as the plants are still feeding, but my theory is less transpiration means less water uptake while there is still enough nutrient in the pot to feed the plants. It also gives the root zone a chance to air out a little. Continual watering during the dark will deliver more oxygen to the roots - as with any hydro system - but then most of that nutrient solution would get flushed out with each watering as the plant is not drinking as much and the nutrient concentration would subsequently be diluted.

This is obviously unique to run-to-waste, as recirculating hydro is continually running.

Again, in my experience (your mileage may vary), overnight drying seems to work best in run-to-waste. I've pretty much tried it all over the years.

ttystikk said:

Better results than green plants and good yields after 10 weeks? They don't want something they're constantly having to screw with; they wanted as close to autopilot as possible and this system delivers!

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Mate, if it works, it works.

All I'm wondering is if you're getting better results with a lower EC and not changing your res out, then the first thought that comes to mind is that there's obviously a build-up of unused salts over a 10-week period that, at higher levels is affecting growth, but at lower levels isn't. If you dumped your res and started afresh every now and then, who knows?

But I'm like you: if something works for someone, maybe it's best to just leave it alone . .

Prawn Connery said:

Well, most soil growers add nutrient/fertiliser at some point, so there's not a lot of difference. In many respects hydro is easier than soil because a good nutrient takes a lot of the guesswork out of feeding - just follow the directions! It's as easy as mixing up a bucket of water with a few ml per litre of Part A and Part B and adding a few drops of pH Down (usually) or pH Up to bring your pH to around 5.8.

Perhaps the easiest way to start would be to simply fill your soil pots with coco and hand-water using an organic-based hydro nutrient like BioCanna or Canadian Xpress (CX). I use CX, which is made up of a mineral salt micronutrient Part A and an organic macronutrient part B, so it's not completely organic like BioCanna, but I've used it for over 10 years with great results. Prior to that I used a fully organic nutrient (A&B Organics), but they went out of business.

You can buy a small pond pump from any hardware store, as well as a digital timer, and then all you need is a reservoir (I prefer food grade plastic) and away you go. Again, run-to-waste is easy because you don't really need to keep check of your reservoir once you've set it up - it just keeps watering the plants, which take the nutrients they need, and the rest is flushed out. All you need to do is top up with fresh nutrient solution and maybe check your pH every now and then (as it will gradually rise in an organic system).

DWC is perhaps the easiest form of hydro and for that all you need is a bucket and an aquarium air pump. You will see the difference in growth straight away. DWC only gets tricky if you grow in a hot environment and have to manage your nutrient temperature. You can still use organic based nutrients if you like. Some people even make their own. Again, it can be as simple as adding Part A and Part B, or as complex as making your own organic tea.

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Honestly, that doesn't sound as easy as easy as using LOS. The only measuring I do is when I mix a batch of soil. I don't even think about ppm or pH.

Humple said:

Honestly, that doesn't sound as easy as easy as using LOS. The only measuring I do is when I mix a batch of soil. I don't even think about ppm or pH.

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I think about ph, after over using compost for a few recycles ph went alkaline and soil was anerobic. Solition, peat, sulfur, aeration and monitor ph of both media and water. ph was not the reason for the issues but an indicator.

Well, think of it this way: if you could increase your yields by at least 30% for the same space and time, and all you had to do was add a teaspoon of this and a drop of that to a bucket of water every now and then, would it be worth your effort?

I mean, you're mixing and potting soil, you're probably watering most days, you either have to dispose of your soil or recycle it after every grow, you have to have some idea of what's in the soil to know what and when to add to it, you've got less control over your nutrients - plus a considerable lag time when you do have a nutrient issue - and your plants grow so slowly, it's kinda painful to watch. Plus it's dirty

Trust me, I've done it and would never go back (at least indoors - outdoors is obviously a different story). For some reason, people always seem to think hydro is harder than it really is . . .

Prawn Connery said:

Well, think of it this way: if you could increase your yields by at least 30% for the same space and time, and all you had to do was add a teaspoon of this and a drop of that to a bucket of water every now and then, would it be worth your effort?

I mean, you're mixing and potting soil, you're probably watering most days, you either have to dispose of your soil or recycle it after every grow, you have to have some idea of what's in the soil to know what and when to add to it, you've got less control over your nutrients - plus a considerable lag time when you do have a nutrient issue - and your plants grow so slowly, it's kinda painful to watch. Plus it's dirty

Trust me, I've done it and would never go back (at least indoors - outdoors is obviously a different story). For some reason, people always seem to think hydro is harder than it really is . . .

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Good points but some context. I have total control orf the nutrients in the soil but do rely on the plants ability to uptake what it needs when it needs it (with some influence from technique). In hydro you have to dictate what the plant gets when it gets it and this should align with plant needs, but you have the burden (or power).

Yes to the lag time and dirtyness but not all bad, I like getting dirty and tend to procrastinate myself.

One adaption I am going to attempt is adding active aeration of the soil, something I will credit hydro growers for the idea of.

Prawn Connery said:

Personally, I don't subscribe to the theory that 50% more light (18/6 vs 12/12) means 50% more nutrient uptake. But that's just me, and for reasons already outlined.

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I never said it's 1 to 1. But yes, the drop in nutrient uptake is substantial. Say 30% to 40%.

Well the difference probably is that I actually feed my plants to what they need in VEG. They easily need up to an EC of 2 in late VEG.

It's no surprise that following the schedule works. If you simply follow the schedule the plants simply grow somewhat slower and less bushy. It's not like they die. So yes it works, but you get more spindly plants and it takes longer. And yes if you veg at a much lower EC than you the plants would actually like then you can maintain or even increase the EC after switchover to 12/12.

That vegging at a lower EC als can be done is not the point. The point is that the plants should get higher nutrient levels before the switchover and no schedule seems to actually do that.

SSGrower said:

Good points but some context. I have total control orf the nutrients in the soil but do rely on the plants ability to uptake what it needs when it needs it (with some influence from technique). In hydro you have to dictate what the plant gets when it gets it and this should align with plant needs, but you have the burden (or power).

Yes to the lag time and dirtyness but not all bad, I like getting dirty and tend to procrastinate myself.

One adaption I am going to attempt is adding active aeration of the soil, something I will credit hydro growers for the idea of.

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Ah, you snuck a post in front of me when I was replying to Humple

A good hydro nutrient has almost everything you find in soil - especially the organic-based nutrients with humic and fulvic acids, rhizo and other beneficial microbes. I add soluble silica to my reservoir, though most tap water has a bit of silica in it.

Having more nutrient control obviously leads to more responsibility. But at it's most basic, you're simply following directions on a bottle. As you get to know your plant and nutrient, you can start to adjust accordingly and will know when and what your plants are lacking (if anything) and how to remedy it quickly.

Soil is an excellent buffer, and very forgiving (though coco also has excellent buffering characteristics), but it's a PIA when you overdo it and have to flush and start again. There's a lot of guesswork involved.

And while soil aeration is good, it usually means you need to add more nutrient to make up for the inert media.

Don't get me wrong - I don't have anything against growing in soil - it's just that I find hydro so much easier and way more productive. I'm probably not good enough to grow in soil

wietefras said:

I never said it's 1 to 1. But yes, the drop in nutrient uptake is substantial. Say 30% to 40%.

Well the difference probably is that I actually feed my plants to what they need in VEG. They easily need up to an EC of 2 in late VEG.

It's no surprise that following the schedule works. If you simply follow the schedule the plants simply grow somewhat slower and less bushy. It's not like they die. So yes it works, but you get more spindly plants and it takes longer. And yes if you veg at a much lower EC than you the plants would actually like then you can maintain or even increase the EC after switchover to 12/12.

That vegging at a lower EC als can be done is not the point. The point is that the plants should get higher nutrient levels before the switchover and no schedule seems to actually do that.

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I won't argue with empirical evidence, and as I don't run recirculating hydro I'm not in a position to measure it myself. The tomato plant chart shows a ratio of about 60:40 (Day uptake vs Night uptake) on a 12/12 cycle. Extrapolating that to an 18/6 cycle shows about a 10% difference in total uptake (if uptake is linear - which it may or may not be). Your results may well be in the ballpark.

Regardless, the interesting thing about the charts is it shows a clear rise in nutrient-to-water uptake at night compared to day due to less transpiration. So without talking at cross purposes, yes there is a case for plants uptaking less nutrient when switching from 18/6 to 12/12, but in fact EC tolerance increases as a result.

Or in simple terms, if a plant requires less nutrient at night, but even less water, then the proportion of total dissolved salts (TDS) it requires goes up. In other words, a higher EC is likely beneficial.

Would you agree?

Prawn Connery said:

... I'm probably not good enough to grow in soil

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Sorry, didnt mean to interrupt. But I call bullshit^^^
And you touched on the number one reason I never got into hydro, the bottles of mostly water that are shipped cross country and over seas (i think canna bio still comes from the netherlands). This reasoning has nothing to do with the efficacy of hydro, just a disagreement with the standard industry practices.

....I'm probably not good enough to grow in hydro

Haha! I know some people who make their own organic teas from scratch for hydro - I'm definitely not good enough for that.

Actually, I'm lucky - CX and a few other decent hydro nutrients are made locally.

FWIW, I like to water/feed in the am, seems the plants just respond better. I would like to know how to correlate EC in organic soil to EC in hydro?

Wietefras also makes an excellent point about proper feeding in VEG but this growth pattern should be matched into flower. Many switch sick veg plants directly to flower expecting great things?? And wonder why they end up with problems "all of a sudden" at week 6? This is true for soil growers too.
The immediate flip to flower done by most introduces that pesky human factor and makes challenging the comparison to available non cannabis specific (or at least indoor specific) agricultural data. IMO

I have been fermenting and doing some knf type things now and would look to use those type technique if (when) I do hydro. Not gonna happen anytime soon though, too much left to learn in soil yet. There is a member in organics section looking to try some sort of rdwc system with organic soil and teas.

Prawn Connery said:

I won't argue with empirical evidence, and as I don't run recirculating hydro I'm not in a position to measure it myself. The tomato plant chart shows a ratio of about 60:40 (Day uptake vs Night uptake) on a 12/12 cycle.

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That sounds incredibly unlikely. Unless they have very high evaporation from their substrate. DWC is a closed system so pretty much the only way the water goes out is through the plants.

Or in simple terms, if a plant requires less nutrient at night, but even less water, then the proportion of total dissolved salts (TDS) it requires goes up. In other words, a higher EC is likely beneficial.

Would you agree?

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First of all I see less than 10% uptake during the dark period. So the amount of nutients taken in during that period a pretty much negligible.

Also the reason the relative uptake is higher is probably because there will be some active uptake when passive uptake is reduced to pretty much zero. That doesn't mean they actually need more nutrients.

The EC drop during the dark period is so small that it's in the hundreds of EC. These things are not accurate enough to even say something about that. I also see the EC rise during the dark period. So even if they would be taking up relatively more during dark hours than light hours, it does not register significantly on a EC meter and therefore would be negligible too.

Prawn Connery said:

Well, think of it this way: if you could increase your yields by at least 30% for the same space and time, and all you had to do was add a teaspoon of this and a drop of that to a bucket of water every now and then, would it be worth your effort?

I mean, you're mixing and potting soil, you're probably watering most days, you either have to dispose of your soil or recycle it after every grow, you have to have some idea of what's in the soil to know what and when to add to it, you've got less control over your nutrients - plus a considerable lag time when you do have a nutrient issue - and your plants grow so slowly, it's kinda painful to watch. Plus it's dirty

Trust me, I've done it and would never go back (at least indoors - outdoors is obviously a different story). For some reason, people always seem to think hydro is harder than it really is . . .

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Once you have a rhythm, reamending and recycling soil isn't a big deal. As for watering and slow growth - SIPs address both of those concerns by making watering an automated no-brainer, and causing a MUCH higher rate of growth than that achieved with standard watering practices (obviously not like the growth you see in a hydro system, but a dramatic difference from top-watering, nonetheless).

And then there's the water itself. My water comes out of the tap pretty hard, so setting up a hydro system would require an RO system, which is more expense and more tinkering.

Then there's just the pleasure of establishing a natural, living eco-system that self-balances. I just really dig the organic soil approach.

But all this is not to say that I think hydro isn't a great way to grow. I just don't think it's for everyone, all the time! Whatever floats your boat! It all comes back to that rhythm - find your groove with whatever medium/method you're using, and keep on trucking.

wietefras said:

That sounds incredibly unlikely. Unless they have very high evaporation from their substrate. DWC is a closed system so pretty much the only way the water goes out is through the plants.

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I don't know how it "sounds" but I do know how it looks:

https://www.jstage.jst.go.jp/article/jjshs1925/60/3/60_3_547/_pdf

Plants require much less water at night in relation to the amount of nutrient they uptake compared to the day.

wietefras said:

First of all I see less than 10% uptake during the dark period. So the amount of nutients taken in during that period a pretty much negligible.

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When water uptake falls at night, nutrient uptake does not fall by the same amount. (See above)

In one case, water consumption fell 80% during the 12-hour-dark period, but phosphorous uptake remained exactly the same as it did during the daytime!

wietefras said:

Also the reason the relative uptake is higher is probably because there will be some active uptake when passive uptake is reduced to pretty much zero. That doesn't mean they actually need more nutrients.

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No, but they do need less water. Which means the plant can tolerate a higher EC during active uptake at night before it is affected by reverse osmosis at the root level and starts to wilt and burn.

wietefras said:

The EC drop during the dark period is so small that it's in the hundreds of EC. These things are not accurate enough to even say something about that. I also see the EC rise during the dark period. So even if they would be taking up relatively more during dark hours than light hours, it does not register significantly on a EC meter and therefore would be negligible too.

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The study proves otherwise but, different plants, different variables.

In any case, EC does not determine how much a plant feeds - it is only an indicator. How much salt in solution (high EC) a plant can tolerate before it affects growth is only partly determined by how much it feeds.

Bottom line ^ this is why your plants can handle the same or higher EC when you switch them to 12/12 regardless of whether they feed less.

I'm sure the nutrient manufacturers came to the same conclusion when they formulated their feeding guidelines.

Ultimately, the plant doesn't give a sh*t what your EC pen reads - it will tell you if it wants more or less nutrient and you can adjust your solution accordingly.

Humple said:

My water comes out of the tap pretty hard, so setting up a hydro system would require an RO system, which is more expense and more tinkering.

Then there's just the pleasure of establishing a natural, living eco-system that self-balances. I just really dig the organic soil approach.

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Hard tap water has its benefits. If it's mostly calcium and some magnesium from a limestone (artesian) source, maybe a bit of iron from the pipes, then it can still work well with coco. NaCl is a different story. This is where EC/TDS meters are found wanting: they only tell you your water is salty - they don't tell you which salts they are.

Coco can have the benefits of an organic system too, but with most of the advantages of hydro. It's one of the reasons why I switched from DWC and NFT.

It was time I had to get busy, but it always break my heart doing it to them
Full strip + some highest nodes got topped.
Flip in 2days.

T-Time said:

It was time I had to get busy, but it always break my heart doing it to them
Full strip + some highest nodes got topped.
Flip in 2days.

View attachment 4141661
View attachment 4141662

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Holy defoliation, Batman!! You're a braver man than I.

Those plant are so resilient to anything I throw at them , I am 95% sure they will bounce back. They always do.

They looked 9/10 healthy before so I knew I could be a bit more brave

Yikes, they're naked! Pure pot porn. Great thread T-Time.

Prawn Connery said:

EC/TDS meters are found wanting: they only tell you your water is salty - they don't tell you which salts they are.

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Good point.
It's why the local hydro store thinks 300 ppm well water could be an issue. What do you think, safe to try in a Hempy bucket with 30% coco?