Can someone explain this LUCAS so called FORMULA to me...

[turbolaser4528]

yeah how much should ppm rise? I would like to find the equilibirum point where ppm stays the same and so does ph but it seems almost impossible, my plants may stay at the same ppm and then I see a huge mg deficiency even at 5.9 ph, so then I ramp up the nutes because I think Im underfeeding, then the ppm rises and ph falls pretty quickly, .4 drop per day maybe, and deficiency dissapers..

but i dont know if this is the right way to do things, I need to reread lucas's thread I think, because I haven't seem him mention these kinds of things and how quickly to upp the nutes like 100 ppm per week or what? know what I mean guys? and girls of course...lol

 

[flat5th]

Man this is frustrating. I've spent countless hours trying to learn all i can and it seems i'm learning it all wrong.

My shit looks pretty good at the moment. So i'm not down and out on growing. I just wish that the last 18 months of intense reading and research wasn't constantly getting flipped. I find one mentor to follow, then someone debunks their shit. So I join that crew and then it gets shot to shit a little while later.

sorry. don't mean to freak out. It's just an exercise in patience and learning that is getting the best of me right now.

It's a slow climb, baby.
Fifth.

 

[Dregs]

I am with ya Flat... I have been reading for a while... finally started growing... and everyday I read things about how I am doing it ALL wrong. I have already spent lots on nutes I don't need.. I think my next batch (popping seeds next week) will be on the lucas.

/sigh One more thing to buy, but hopefully will be the last.

 

[10k]

one thing to consider when looking at all the ph charts showing availability is that they are depicting ideal ranges for uptake of each element. it does not mean that lockout occurs precisely at the points illustrated

Yea sorta delta...BUT...
The element availability pH charts have NOTHING to do with what happens to chemical mineral salts hydro nutrients and how portions of them percipitate in solution, (thus becoming totally unavailable to the plants) inside the reservoir AND within the mediums. This is a source of major misunderstanding and plant problems for hydro growers using chem hydro nutrients.

Furthermore, people following that g'damned (and totally wrong) square bar style pH chart that's been going around here at icmag think they're doing the right thing running an initial pH of 5.8, when that is actually the exact point of the least mg uptake availability...and... they think they're getting more P & K at higher pH values...but in chemical reality the exact opposite is what is actually happening IN their nutrients !

Not to mention just how f'ked up and "damaged" their hydro reservoir solutions are getting by improper mixing, improper pH'ing and totally messed up, so called "add back" or topping off strategies. That's another major mistake people are making contributing to their frustrations and plant problems running true chem hydro grows.

I've been bitching about poor gh mixing and maintenance techniques for years, but it goes right over a lot of folks heads...arrrgh !

 

[Hydro-Soil]

my plants may stay at the same ppm and then I see a huge mg deficiency even at 5.9 ph

Well yeah...... 5.9 is terrible for mg.... Bump your pH up to 6.0-6.1 for 2 weeks. Next time mix your res at 5.2 at the beginning. From what I've read of others doing that with FNB, you shouldn't experience the deficiency then either. Should take care of itself.

 

[MarquisBlack]

Listen to Hydro Soil. There are alot of us who figured through research that 5.8-6.0 would be the ideal range, but trust me, if you start at 5.8 you're going to see a mag deficiency at about 4 weeks in. Do what he said and start at about 5.2, let it drift up to 6.1 through week 4 and drop it back down again. That long steady pH drift, once basic, and once back toward acidic is key.

 

[REZDOG]

See the thread labeled "The Recipe" in my forum,it's a modified (over a dozen years!)
"Lucas Formula",that,imo,works a lot better.

Cheers!

 

[turbolaser4528]

Well yeah...... 5.9 is terrible for mg.... Bump your pH up to 6.0-6.1 for 2 weeks. Next time mix your res at 5.2 at the beginning. From what I've read of others doing that with FNB, you shouldn't experience the deficiency then either. Should take care of itself.

When I mix my nutes it comes out around 6.0, so you are saying I should ph down a low strength nute solution so that the ph will rise because the plant needs more food, and then give it more nutes once ph reaches 6.1 so that the ph drifts down naturally to 5.2. Then I should change out the res and do it all over again??? I thought most people feed slightly heavy, how will I know how light to feed? my ph always seems to stay at 5.9-6.0 or drop I never get it to rise. Maybe I should use less nutes? then i get heavy deficencies, ahhhhh fuckin hydro I need help here i'm more lost than I thought.

Listen to Hydro Soil. There are alot of us who figured through research that 5.8-6.0 would be the ideal range, but trust me, if you start at 5.8 you're going to see a mag deficiency at about 4 weeks in. Do what he said and start at about 5.2, let it drift up to 6.1 through week 4 and drop it back down again. That long steady pH drift, once basic, and once back toward acidic is key.

how do I do this exactly?

 

[Hydro-Soil]

Listen to Hydro Soil.

Listen to 10K!
They know this stuff waaaaay better than I do. I totally agree with where they're coming from. I seem to recall 5.2-5.5 being the optimum range being touted about 6 years ago on OG and CW.....

Things constantly flip-flop, especially in an underground community!

 

[dongle69]

The medium that you use will dictate what is the ideal ph range.
Coco isn't the same as hydroton, which isn't the same as rockwool, and so on...

 

[turbolaser4528]

Yea sorta delta...BUT...
The element availability pH charts have NOTHING to do with what happens to chemical mineral salts hydro nutrients and how portions of them percipitate in solution, (thus becoming totally unavailable to the plants) inside the reservoir AND within the mediums. This is a source of major misunderstanding and plant problems for hydro growers using chem hydro nutrients.

Furthermore, people following that g'damned (and totally wrong) square bar style pH chart that's been going around here at icmag think they're doing the right thing running an initial pH of 5.8, when that is actually the exact point of the least mg uptake availability...and... they think they're getting more P & K at higher pH values...but in chemical reality the exact opposite is what is actually happening IN their nutrients !

Not to mention just how f'ked up and "damaged" their hydro reservoir solutions are getting by improper mixing, improper pH'ing and totally messed up, so called "add back" or topping off strategies. That's another major mistake people are making contributing to their frustrations and plant problems running true chem hydro grows.

I've been bitching about poor gh mixing and maintenance techniques for years, but it goes right over a lot of folks heads...arrrgh !

do you have links to threads where you explained all of this?

I'd love to pick your brain (such a strange expression right?) or can you explain the proper hydroponics techniques in a thread and then have it stickied perhaps? i'll understand if you don't want to I hate repeating myself as well, but if its not too much trouble.....

I think that would help a lot of hydro folk who are practicing improper techniques.

 

[Asil]

I would suggest taking what 10k and hydro say to heart. They really know their hydro. I spend hours upon hours reading and researching, and find that there is truth in what they say. Also I have been looking a REZ's "receipe", I mean could you really argue and deny the fact that this guy puts out some awesome genetics. I may just run his receipe with some of his genetics. The "Receipe" has alot of validity, and pretty close to the Lucas Formula. There is more work involved though. Either way I believe both will produce excellent results and great yeilds!

 

[Carboy]

See the thread labeled "The Recipe" in my forum,it's a modified (over a dozen years!)
"Lucas Formula",that,imo,works a lot better.

Cheers!

Would someone mind posting the link to this?
I tried Search, but i must be dense.

TIA

 

[Asil]

Carboy here you go http://icmag.com/ic/showthread.php?t=81674

 

[Hydro-Soil]

When I mix my nutes it comes out around 6.0, so you are saying I should ph down a low strength nute solution so that the ph will rise because the plant needs more food, and then give it more nutes once ph reaches 6.1 so that the ph drifts down naturally to 5.2. Then I should change out the res and do it all over again???

No. Sorry if I was unclear but that's not it at all.
Mix your solution full strength. What's your pH? If it isn't 5.2, adjust it to 5.2. Now, leave the pH alone and don't touch it. Just top off with RO water, keeping the same level of water in the res as there was when you first filled it.
If you're only able to test pH, dump the res and re-mix when you've added back the same amount of water that you started with. (10 gallons mixed, 10 gallons added back) Mix a fresh res.

If you can check EC/tds then you want 900-950ppm @.5 conversion or [email protected] conversion. Keep the res topped off with RO water and add nutes every few days to keep the ppm within the range for your meter. You can keep adding RO water and nutes for 2-3 crops before most folks say they have to change the res.

Either way you're NOT going to mess with the pH often at all, if ever. The GH nutes are buffered and the pH up/down you use goes away slowly. The pH will slowly drift up and down within an acceptable range. Whatever you do, don't continually adjust your pH to keep it within a specific range.

Now...... if you didn't start your res this way you'll most likely see a deficiency at weeks 3-4 of 12/12. The FIX (since the res wasn't mixed properly the first time) is to raise the pH to 6.0-6.1 to make the mag in the nutes freely available. This will FIX the situation. If you start with 5.2 you shouldn't see that though.


Does that make more sense to you?

 

[turbolaser4528]

No. Sorry if I was unclear but that's not it at all.
Mix your solution full strength. What's your pH? If it isn't 5.2, adjust it to 5.2. Now, leave the pH alone and don't touch it. Just top off with RO water, keeping the same level of water in the res as there was when you first filled it.
If you're only able to test pH, dump the res and re-mix when you've added back the same amount of water that you started with. (10 gallons mixed, 10 gallons added back) Mix a fresh res.

If you can check EC/tds then you want 900-950ppm @.5 conversion or [email protected] conversion. Keep the res topped off with RO water and add nutes every few days to keep the ppm within the range for your meter. You can keep adding RO water and nutes for 2-3 crops before most folks say they have to change the res.

Either way you're NOT going to mess with the pH often at all, if ever. The GH nutes are buffered and the pH up/down you use goes away slowly. The pH will slowly drift up and down within an acceptable range. Whatever you do, don't continually adjust your pH to keep it within a specific range.

Now...... if you didn't start your res this way you'll most likely see a deficiency at weeks 3-4 of 12/12. The FIX (since the res wasn't mixed properly the first time) is to raise the pH to 6.0-6.1 to make the mag in the nutes freely available. This will FIX the situation. If you start with 5.2 you shouldn't see that though.


Does that make more sense to you?

Lol yeah buddy thanks that does make more sense.

I have a question, If I am adding nutes as well as water to keep within that ppm range then how is the ph going to rise? Because nutes lower ph so......


FYI, I have one scrogged widow in a 30 gallon rez that was vegged for only 3 weeks, ~18 days into flower under a 400whps in a 3x2x7 armoire, so it doesn't lower the water level that much, even though the stem is half an inch thick and the plant takes up almost the entire cab.

I do have a ppm/ph meter, its that expensive hanna one. ppm is at 1000 at a .7 conversion and the ph is still dropping, so i'm going to add water and bring it down to say 800ppm? ph will be 6.0-6.1 then. Still seems too weak to me, 1300 ppm seems unattainable ahhhhhh!

 

[Hydro-Soil]

I have a question, If I am adding nutes as well as water to keep within that ppm range then how is the ph going to rise? Because nutes lower ph so......

Glad that run explained it a bit better for ya.

The pH will only rise too high if you're not keeping the concentration of nutes high enough for the amount of light the plants are converting. If your pH keeps rising, increase the strength of your nutes. If you're running super intense lighting and CO2 you'll probably find this level to be higher than 1400ppm. I haven't seen it yet.

 

[washed up]

I have some questions about the Lucas formula, and I hope you can answer my questions. What is the NPK of Lucas?
What are the various percentages of N?
I have used Lucas before almost described to the tee, topping off with water, but I kept my PH around 6, lankier longer flowering plants love it, my short n stout indicas showed various signs of deficiencies by the 3rd week of flower, that I went back to 1-2-3 to remedy the problem but still had to fight mg. D with cal mag n Epsom salts. What damage was done was at least fix the issues, and roll from there. At week 5 I cut the cal mag, week 6 the grow back to Lucas for 2 weeks n flushed. My yield wasn't affected that much, but they finished a few days earlier.

I will try 5.2-5.5 and see if that helps but I usually start hi (6.3) and lower the set ph .10 every week til I get to 5.5 and flush with 5.5 too. I do let it rise about .3 before changing my rez. My personal opinion is the green might not be a neccesity in all strains, but I don't think it hurts to add it to a rez running multiple strains. A friend uses GH in equal parts then reduces the green a month in to rec. Dose throughout til flush with great success.
Thanks for answering my questions!

 

[10k]

do you have links to threads where you explained all of this?

I'd love to pick your brain (such a strange expression right?) or can you explain the proper hydroponics techniques in a thread and then have it stickied perhaps? i'll understand if you don't want to I hate repeating myself as well, but if its not too much trouble.....

Yes, I'll write something up real soon, I did write a mixing and maintenance post a while back but it was kind of specific to the thread starter in that thread.
I'll have to re-do another as it's own thread when I have more time.

I think that would help a lot of hydro folk who are practicing improper techniques.

Yes, I just about choked on my coffee when I read this misconception below...
(and I covered my eyes when I saw the leave the pH alone thing...sheeesh)
I don't have a lot of time right at this moment, so I'll try to keep it short, but I'll elaborate further in it's own thread real soon.

Keep the res topped off with RO water and add nutes every few days to keep the ppm within the range for your meter. You can keep adding RO water and nutes for 2-3 crops before most folks say they have to change the res.

Adding nute chem hydro nutes in their concentrated form to an already mixed reservoir is about the second most disasterous thing a person could do to their nute solutions and their plants. Chem hydro nutes can be damaged just by the way people mix them causing certain elements to precipitate within the solution thus becoming unavailable and useless to the plants. People can even damage them in the same way just in the process of adding concentrated pH'ing chems and other additives or snake oils in too concentrated form or in the wrong sequence.

And trying to keep adding water and nutes for one full season could have an outcome only frankenstein could possibly imagine, a recipe for several disasters, not even thinking about how horrible it would be to try to carry out the flawed process to the same mix over several crops...impossible !

We need to think about plant nutrition in mass balance...
Plants in hydro uptake different elements at differing rates and speeds, leaving behind what they didn't want or couldn't uptake.
Over time the nute solution changes to levels which would contain toxic levels of certain elements and major deficits of other elements,
which is why it is important to have a good res changing and maintenance program too.

Metaphorically speaking, you cant give a child a big piece of chocolate cake and then expect him to be able to eat his dinner.
We would have to feed the kid his dinner and then let him have the chocolate cake after he finished diner.

Most add back strategies are highly flawed, even if the chems are added properly, in that they don't take into consideration what levels of elements have been removed by the plants and what element levels are still remaining in that reservoir being added to with more nutes. Doing so over a long time frame only worsens the problem which is why it is important to dispose of the res solution and replace it from time to time instead of trying to maintain it based on it's tds measurement.

You'd need to have an GCMS machine to do plant tissue analysis and nute solution analysis in order to properly add back all the elements in the correct amounts to maintain a chem hydro reservoir over a long term time frame. We hobby growers just don't have the facilities to do such high tech processes.
We are much better off just replacing the res solutions with fresh mixes before it has a chance to become poisonous to the plants.

pH is very important and plays a role in plant nute uptake and also a role in how and when elements precipitate in the chemistry and become unavailable to the plants. Chem hydro running in hydro mediums works best if its in the range of 5.1 to 5.9, with 5.2 being the optimal res starting range. It's good for the plants to allow the range to drift through the range rather than trying to hold it to a tight number all the time. The plants get exposed to a fuller spectrum within a pH range than they would in a tight pH number.

We want them to have everything on the plate available, not just the chocolate cake.

later,
10k

 

[dongle69]

I hope my plants don't see 10k's posts.
They don't know that they shouldn't be doing so great.
Please nobody tell them.

The beauty of the Lucas formula is that it is already a properly balanced "diet."
It is so simple that some make it sound complicated.
I am constantly experimenting myself, but Lucas formula has always worked for me.

Remember folks, it is O.K. that people do things different from you, and you can do things different than them.
If my plants are happy, I'm happy.