Ph issues with Lucas Formula any advice???

Rick Ratlin

Active Member
By my calculations in my excel spreadsheets, that 0-8-16 ratio equals 1240ppm (.7 conversion) or around 1.8 EC.

The grow only has an NPK rating of 2-1-6, not exactly the nitrogen powerhouse. If you added it and kept plants healthy, more power to you. In regards to your feeding levels, do what works best for you, your environment and your plants. I can tell you this much, I would never, ever, ever, feed at those levels, ever. My experience and tests have shown me that if you put food in your res in modest concentrations, the plants will be able to pick and choose what they need to pull up. As long as you're not underfeeding certain elements or locking out others by overfeeding or feeding in bad ratios, you're going to get great results. There is more to this than 'just do what you think works best' but I feel like everyone needs to live and learn.
Thanks for the free experience HB. Live and learn is a true motto lived so far. I've got a 2 week per tray, 4 tray sog system, and day after tomorrow the new flowering tray is going in at a lower level. Can you reveal your GH exel spreadsheet numbers or any recommendations for my new gh 3 part ratio? Is there anywhere that has a cumulative GH cannabis ratio recommendation sheet?
 

homebrewer

Well-Known Member
Can you reveal your GH exel spreadsheet numbers or any recommendations for my new gh 3 part ratio? Is there anywhere that has a cumulative GH cannabis ratio recommendation sheet?
I just use about 5 mls/gallon of micro to start, then the rest of my ppms are from florabloom and koolbloom (which are the same product). Midway through flower, I cut back to 4 mls/gallon of micro and the rest of my ppms are from florabloom and koolbloom. I start flower at 1.1 EC and top out anywhere between 1.3 and 1.6 EC depending on the strain. It's not my favorite nute line to work with these days but it certainly works very well.

The only thing I don't like about the 3 part systems out there is that the nutritional needs of the plants will change throughout flower so when you should be feeding higher nitrogen during the first 3 weeks or so, it's impossible to scale back nitrogen late in flower without cutting back the micro nutrients since they're all in the same bottle. Basically, more of my ppms late in flower are coming from nitrogen than I prefer when using the 3 part and I've seen that hurt my yields.

The only reason I brought this up is that I've noticed that when I was overfeeding, my plants were not taking in nutes and water in the same amounts which would cause my pH to drift. Only after 3-4 adjustments and topping off with tap water would it finally stabilize.
 

pitbull420

Well-Known Member
Ok well I have tried everything suggested including soaking the hydroton, letting the water sit over night and using distilled water instead of the tap but after a res change it still takes me about a week to stabilize my ph.. So I have come to the conclusion that the ph swing has to be caused by the GH nutes.. It's a pain in the ass to have to adjust the ph daily but until I use up all these nutes I guess I'm stuck.. Think I'll go back to FF when I'm done...
 

hellraizer30

Rebel From The North
I had ph swings with gh to and I went with advanced g/m/b and b52 / big bud / overdrive and my shit is off the hook, not trying to
sell you on it, just saying you might want to check it out. FF has its issue to ive used it also, only difference from the GH ph swing
was with the ff the ph went down. my ph with advanced is rock solid 5.8. just hit me up or pm me if you got some Q. peace
 

MoJobud

Active Member
Ok well I have tried everything suggested including soaking the hydroton, letting the water sit over night and using distilled water instead of the tap but after a res change it still takes me about a week to stabilize my ph.. So I have come to the conclusion that the ph swing has to be caused by the GH nutes.. It's a pain in the ass to have to adjust the ph daily but until I use up all these nutes I guess I'm stuck.. Think I'll go back to FF when I'm done...
How are you taking your measurements? I have a 55 gal res and I keep a powerful pump in there to circulate the water 20 min prior to feeding and I can tell you that the solutions ph reading as well as ppms can vary quite a bit from the top to the bottom of your res tank. I keep a submergible three way meter and from the bottom of the tank to the top, readings can swing .5-.7in ph value or it's just the way the meter reads it.
 

hellraizer30

Rebel From The North
my 55 gal res has a little gaint pump in there and it runs 24/7 mixing the res giving me a constant consistant way to test PH/ppm
 

pitbull420

Well-Known Member
How are you taking your measurements? I have a 55 gal res and I keep a powerful pump in there to circulate the water 20 min prior to feeding and I can tell you that the solutions ph reading as well as ppms can vary quite a bit from the top to the bottom of your res tank. I keep a submergible three way meter and from the bottom of the tank to the top, readings can swing .5-.7in ph value or it's just the way the meter reads it.
I take a cup full of the solution out of each bucket and test the ppm and ph twice a day.. Using a Hanna digital Ph meter along with a HM digital tds meter.. Then add back ph down to stabilize the ph as needed... I usually have to adjust the ph every morning..It's a pain in the ass and is taking a shit load of ph down to maintain the proper ph level.. I'm already half way through a quart and not even a quarter way through the grow.. Has any one here ever tried white viniger for ph down?? I only ask because the nearest hydro store to me is 200 miles away and ordering onlines a pain..

I had ph swings with gh to and I went with advanced g/m/b and b52 / big bud / overdrive and my shit is off the hook, not trying to
sell you on it, just saying you might want to check it out. FF has its issue to ive used it also, only difference from the GH ph swing
was with the ff the ph went down. my ph with advanced is rock solid 5.8. just hit me up or pm me if you got some Q. peace
Yeah I've heard good thing about Advanced nutes but I just can't see paying as much for nutes as I did for my 600watt light lol.. Especially because I grow to support my own habit not to sell... So all the money spent on my grows is just the money I save on buying bud lol..
 

hellraizer30

Rebel From The North
advanced aint that much $ the sup are where the cost is and you dont even need that stuff. the g/m/b is all you realy need.
I know this cus a buddy is using the 3 part with no sups and his look great, so my next run im not going to use the sups.
the cost for all three in 1 gal per part was 87bucks and when I used Gh three part it was over 100$ and I had to use sups
to stop def. so im my mind im saving a shit load using advanced. and FF if you price it out with all the sups is a car payment lol
 

homebrewer

Well-Known Member
AN copied GH's 3 part formula, so did cutting edge, humboldt, and super natural. Moving from one 3-part to the other isn't going to solve any issues here.
 

hellraizer30

Rebel From The North
AN copied GH's 3 part formula, so did cutting edge, humboldt, and super natural. Moving from one 3-part to the other isn't going to solve any issues here.
well I dont believe there the same in anyway other than the 3 part concept, AN is way more stable over GH so if the nutes are the same owell but
the additives they put in it to help buffer PH is better in my opion.
 

Irollfatties

Active Member
Okay i definately didn't read through all the replies, but scanned through them and did not see a rez temp which could greatly affect ph. And Hydroton does not need to be soaked, atleast from my experience and from what i've read. I just throw the hydroton straight in and i've never experienced ph issues. I also agree that the lucas formula is a tad high. A couple of my girls burned when i ran staight 0-8-16. I don't know the exact measurement but i keep my rez around 700-750 on a .5 scale.
 

hellraizer30

Rebel From The North
Okay i definately didn't read through all the replies, but scanned through them and did not see a rez temp which could greatly affect ph. And Hydroton does not need to be soaked, atleast from my experience and from what i've read. I just throw the hydroton straight in and i've never experienced ph issues. I also agree that the lucas formula is a tad high. A couple of my girls burned when i ran staight 0-8-16. I don't know the exact measurement but i keep my rez around 700-750 on a .5 scale.
i think the lucas being to strong or to week is dependent on the strain you have, one of mine will grow perfect in 600ppm all the way through and my other
thrives at 1300ppm as for lucas I abandoned it due to def. I 100% agree with you on the tron I dont prep it all just throw it in and rock and roll no Ph issue
to report on that.
 

Irollfatties

Active Member
i think the lucas being to strong or to week is dependent on the strain you have, one of mine will grow perfect in 600ppm all the way through and my other
thrives at 1300ppm as for lucas I abandoned it due to def. I 100% agree with you on the tron I dont prep it all just throw it in and rock and roll no Ph issue
to report on that.

Yeah i'm moving to the Canna line after i finish through this Bloom bottle. I will say, on the cheap Lucas helped me save some money and has done a decent job so far.
 

homebrewer

Well-Known Member
well I dont believe there the same in anyway other than the 3 part concept, AN is way more stable over GH so if the nutes are the same owell but
the additives they put in it to help buffer PH is better in my opion.
You mean bicarbonates? Because I'm sure the OP has an excess of them with his crappy tap water which could be another reason why he's seeing a constant pH rise.

OP- Are you use Hard Water Micro? You may want to or look into an RO unit.
 

pitbull420

Well-Known Member
Yeah I'm using the hw formula and also tried using distilled water which made absolutely no difference..
 

pitbull420

Well-Known Member
As far as temp goes just checked all 4 buckets and there all between 69 to 71 degrees fahrenheit.. Is this good or bad????
 

Irollfatties

Active Member
That's good. Anything above 72 is questionable. I'm actually at about 75 but I have high powered air pumps to make up for it. No light can get down the Rez right? The roots don't smell? Rot root cause ph fluctuations. Other than that I can only say an RO will help. If you do get an RO system don't forget to get some calmag. Lucas always says anything under 300ppm is good but I would want to get it a lil closer to 0. I'm lucky enough to have 120ppm on a .5 scale out the tap so really I don't know about RO.
 

pitbull420

Well-Known Member
There is no lightleakage int the buckets at all and the roots look great.. O'well I guess I'll just have to spring for a RO system.. Thanks to everyone for all the help.. I posted this up on a couple other forums and got lil to no replies..
 

homebrewer

Well-Known Member
There is no lightleakage int the buckets at all and the roots look great.. O'well I guess I'll just have to spring for a RO system.. Thanks to everyone for all the help.. I posted this up on a couple other forums and got lil to no replies..
I'd recommend RO regardless of your nutes just because your water is pretty bad. If you still have pH issues after you switch to RO, check out DynaGro. It will easily out perform any 3 part system (since they're all the same) at less than half the cost.
 

PetFlora

Well-Known Member
Lucas is like putting a band-aid on a shotgun wound. Stop recirculating your nutes. doing so is a hugely bad idea
 
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