Lucas Formula and 1700 PPM

[yamaha_1fan]

I thought the Lucas formula was supposed to keep your PPM under 1000?

I decided to run the Lucas formula on my new table. 8ML micro/16ML Bloom per gallon, my calculation tells me I should be using 1440 ML micro and 2880 ML Bloom.

Well after adding and mixing, my PPM was about 1700. Any ideas?

Is it possible the dust off the hydroton raised the PPM?

 

[vigilo]

the lucas formula should be renamed the lucas ratio.
there is no limit on ppm, but the 0:1:2 ratio must be maintained (G:M:B)
I start my clones on 200-300 ppm.
I dont hit 8ml-16ml /gallon until mid flower. if thats where you are, 1700 is fine. if you are still vegging, keep it under 1000.

 

[sunnydog]

Sounds a bit high. Mine would settle in at about 1340. Whats your starting ppm?

 

[Guest]

what ppm meter are you using? .5 or .7?
also lucas says full strength under hid right from the start. Also you must use ro water, what is the ppm of the base water? 0-8-16 should read 1000ppm or near

 

[SB7]

You're running a 180 gallon tank ? wow that's big. For me, 0-8-16 yields an EC approx = 2.0 . (Why does anyone use ppm's in this day and age ?)
That would be approx 1400 ppms (@.7) or 1000ppm's (@ 0.5)
It will also depend on your water ppm's before you add the nutes. Generally you can add the two but it will depend on the specifc salts in your water.
IF your water is 300ppm to satrt, I'd really think about going to RO. It saves alot of hassle in the long run.
I run E&F in hydroton and the dust has no effect on my nute EC (ppm)

 

[yamaha_1fan]

usually my water is like 45ppm, today it was 75.

I thought I read somewhere his goal is to keep it under 1000PPM. Also I dont see in his formula where he progresses his nute strength. Its like on/off.

I dont know which factor the pen uses.

These are clones going into 12/12.

My other table was running 1400-1500 PPM, but a different formula, and they were fine. I used week 4 or 5 of the Lothar formula found in the OG FAQ. I think this may be a tad high for my babies but they have already been on 400 PM veg nutes

 

[SB7]

Well, yes, the idea is to run an EC =2 ( 1000ppm @.5) . I find that is tad high for some of the strains I grow, so I like to keep it 1.8 to 1.9 ( 900ppm to 950ppm)
Lucas always stated that he liked to run a constant nute level as soon after rooting as possible . The only time he'd use lower nutes was under lower light.
If the plants are under HID then use full strength. There is no ramping up of nute levels.
As for no ppm limits, If you're running significantly less than 0-8-16, under HID, then you are probably mag deficient. Lucases theories are based on Mel Franks Cannabis nute requirements. There is an excellent thread "Ask Lucas" over at ... dare I say it C-W. It's got some good info in it and Lucas regularly responds.
Of course every grow is different and no rules are written in stone. These are just guidelines.

My last 3 grows, I switched to FloraNova Bloom ( roughly 8 ml /gallon) and it's worked very well. 1 bottle , that's it Well along with Sub culture.
1 res from start to finish . Couldn't be easier.
As for your high ppm readings, I'd mix up a small batch and test again. Say 2-3 gallons and see what you're reading. My first thought was perhaps an uncalibrated pen , but as you're reading 45-70 ppm for your water that now seems unlikely.

 

[Guest]

^^^^^^^^^^^^^^^^^^^^^^^^^^^
based on the above with my tap water at 300ppm what is the highest you guys think i should go(tds3 .7?), i am doing 5/10 in bloom right now so i'm far on day 12, im afriaid that 8/16 will burin my sd-og and c99-og, i'm not even sure my dabney or casey's could take that with the tap like that, whatcha guys think go up to 1600pm and say fuck it curiently at 1350ppm with the tapp...

 

[upgradeshafted]

watch the plants man they will tell you if its to hot...i dont use a ppm meeter at all..peace...are you using hardwater micro?

 

[Guest]

Nope regular mico, i'm tring to start to use a ro but get 10gal a day lol.

 

[Guest]

I dont know which factor the pen uses.

Uhhhh....

Why does anyone use ppm's in this day and age ?

I dunno...ppm is arbitrary...ec is not. You can have 2 people talking ppm and if using a different conversion factor they are talking Japanese and Urdu. EC is the universal language here.

 

[upgradeshafted]

i agree nondual i have watched people screw up other peoples plants because thier meeters are calibrated differently and the person folowed the pen...a pen is just another tool learn to read your plants...if you read the plant and not the meeter then your growing...i only use a ph pen and i replace it every year...i use a proven nutient mix with ro water...ppm dont matter to me just something to complicate what i find simple...ph is everything...peace

 

[eLiguL]

I dunno...ppm is arbitrary...ec is not.

I believed this to be true as well but it isnt. EC pen's also come in different conversion just like PPM pens.

My EC pen is in µs/cm and some EC pens come in ms/cm. I bought the incorrect conversion on my pen and it only reads to a maximum of 2.0EC on your pen, it looks like 2000EC on my pen.

Be careful people and make sure your EC pen reads in ms/cm and not µs/cm.

 

[Guest]

My EC pen is in µs/cm and some EC pens come in ms/cm.

You're basically right but you're talking about moving a decimal point 3 places and not about the difference in PPM's being converted from EC by either a .5 or .7 factor. Two people talking about PPM's using different conversion factors can cause problems cause they both may be saying 1500 PPM but the actual nute strength is different. I saw one person switch to Advanced Nutrients and they use a different conversion factor and the dude totally fried his grow. I don't know all the specifics but basically that's what it was. When talking EC if someone says 2 and another 2000 the 'discrepancy' sticks out like a sore thumb so any miscommunication is quickly clarified.