Hey there, On 6th week from seed in rdwc. My first time trying the latest version of the Lucas formula. I really am having a tough time getting the ppm in the range he describes. I start with filtered water around 90ppm. After just a little over half strength of what he recommends I'm hitting 1900 ppm. WAY over. My plants don't look to bad but not nearly as green as when I did the 3 part fox farm. I would like to try to stick with the Lucas formula because of the simplicity if at all possible. Please let me know what variable I'm messing up because I'm stumped . IT seemed totally fool proof for this fool thanks
You sure you are calculating properly. What is your set up? How much of each are you using? How many gallons? Is your ppm meter calibrated?
Lucas at 0-8-16 can be ridiculously high for some RDWC systems all depending. It has been in mine for sure...off the charts ridiculously high, and it will cause you problems with micronutrient uptake, once again in some systems. Try dropping down whatever it takes to get under EC 2.0 and I bet it will improve for you. Drop it down lower, to like EC 1.5 and it might get even better for you. It does for me.
thanks for the replies! @zoomme My set up : RDWC, 4x5gallon plant buckets, 1x5gallon controller, 16 gallons total water, PH 5.8, 68-78 F air temp, 70 F water temp. My intention was 8ml per gallon GH flora nova bloom, but only got to about 5ml before ppm was out of range. The meter has been calibrated. @bhp70 I added more water to bring down my ppm to 1500 (in range according to Lucas). Still this brings down the amount of nutes to far below what he recommends. What would you do in this situation? Should I just scrap trying this method and go back to my regular fox farm 3 part? Have you had success with this after you corrected for the high EC?
Yes sir, absolutely...RDWC is a different beast in my opinion and in my experience with it. I'm not gonna set myself up for the needless bickering that goes on here to detail anything, but yes I consistently see problems with running traditional Lucas values in my system. Like anything in this hobby, YMMV. But to simply answer your question, yes. I've run Flora and FloraNova, and always see problems with iron, zinc, calcium being locked out when running at traditional values. My theory for this is that the continuous replenishment of high levels of P and K in some of these systems can be a recipe for micronute lockout. Try it out for yourself...you won't fuck things up by going easy, but you sure can by driving too hard. RDWC you have to be willing to play with a little bit to find your sweet spot. I'd advise you to be wary of anyone's advice, experiment for yourself, and always remember the old adage that sometimes "Less is more." Check out Heath Robinson's Tree Grow thread on IC, and see what he says about EC values in RDWC. The basic Lucas ratio works well, but to get the EC down to a 1.2 to 1.6 range you do need to back way off. It works for me.........maybe it will work for you, but who knows. I have no idea how you manage your growroom, so I ain't gonna make any blanket statements for you. I do certainly wish you the best of luck with it. Give it time and you'll get it figured out.