Leaf Spotting 4.5 Weeks Into Flowering

Hello everyone, I've been lurking in the shadows using everyone's knowledge on this forum for awhile. This is my 4th grow and I've been learning more and more each time. I had a stroke of beginners luck with my first round with Pure Power Plant, which consequently has become my favorite strain. To keep it short here is what I'm using and here is what my problem is 4.5 weeks into flowering. I have been watching small brown spots on the leaves slowly get worse and worse effecting only one strain in the box out of three total strains.

I am flowering 4 plants in a 4' x 4' x 7.5' box well ventilated with air coming in and out. (1) Top 44, (1) Crystal and (2) Pure Power Plant.

Fox Farm Ocean Forest growing medium, no mix each in 3 gallon pots, drain holes and drip pans included.

(1) 600 Watt HPS hood with exterior ducting to remove excess heat and 4 flowering T5 bulbs on the walls to help stimulate side and lower growth. Distance from tops are 12"-15" at most times.

Heat averages 72-76 degrees and humidity is around 32%. Overnight (lights out) temps range somewhere around the 60 degree F area.

Nutrient regiment follows Foxfarm's feeding schedule and water is PH set between 6.3-6.6 per the feeding chart's recommendations from start to finish. Initially I thought the issue was a calcium deficiency so I have been using CalMag with, Superthrive and Thunder when applying straight water (every other watering).

I control the vegging of the plants to produce multiple tips as opposed to one large one. This is the best management of the vegging I have been able to achieve yet.

The Crystal and Top 44 plants look absolutely beautiful, no blemishes or unhealthy leaves at all. However the Pure Power Plants aka PPP are showing signs of severe sickness. The bud development does not seem to be effected at all, but there is a lot of time left and I am hopeful this can be fixed to a degree to keep my harvest in line.

Is it possible that this plant likes a higher PH? I'm lost now, I've been using CalMag for several weeks. Check out the pics attached and all input is welcome! Thanks to everyone willing to offer input

Bumping up, hoping this will be an easy one for some more experienced growers.

You sound like a pretty intelligent guy. I think you're on the right track.

Calcium is definitely the initial diagnosis, but it doesn't fit given the time of life. As the problem goes it's definitely an immobile element... could be related to phosphorus despite not looking much like that. Molybdenum, Boron, Copper... All immobile but needed in such low quantities it makes them unlikely as well.

I think the pH thing is probably the issue when considering the options and the solutions provided. You could have washed out your buffer, media could be a little acidic. I'd run at 6.5 to 6.7 for a feeding or two and see if the problem continues. If it does... I guess flush and rebuild.

Nice, thanks for the reply. I'm going to go with that. My first grow with PPP I don't think I even had a PH meter and they turned out fantastic. My PH runs about 7.5 from the tap which is well water. Given that the possibilities you are suggesting are needed in such low quantities and the FF regiment provides all of these, it brings me full circle back to PH. In your experience do different strains flourish better in a different range of PH? Any experience with PPP? Thanks again.

I tell you I had the say problem my first grow FFOF nothing added in 5 gallon pot had cal-mag issues flowering on alot of the girls. How I combated this was couple teaspoons of dolomite lime mix with your FFOF before transplanting. Not only does it keep your ph stable (dolimite lime has ph of 7), also gives the plants that cal mag that is washed out the soil FFOF is def lacking in cal mag in my experience. One last thing FFOF use crushed sea shells for cal mag not super effective in long run.

Thanks Jdubb! Awkwardly, this is only effecting one strain. I would be skeptical to add the dolomite lime because I would be concerned it might throw my PH off from my nutrient solution. At this point, I think that would be good for these strains since I'm not so sure it is calcium or magnesium, but maybe PH since I've been giving them CalMag supplements throughout the entire flowering cycle. Dolomite lime might allow me to give them supplements of calcium while raising the PH slightly higher than the other unaffected strains while using the same nutrient solution. Here is a question for you Jdubb. If you are giving them dolomite lime via soil during transplant how is it effecting the PH runoff? Meaning what do you use for your PH nutrient solution and how does your runoff compare relatively? Just curious, thanks again for your input.

Dolomite doesn't really raise the pH. It buffers it. It will bring a high pH down and a low pH up.

I concur that it would make a great amendment to the Ocean Forest. Personally, I think their soil has really gone down in quality over the last few years and amending the stuff is the best way to get it working right.

Sweet, good info guys... Having said that what are your thoughts on this....

FFOF mixture with perlite, peat moss and dolomite lime.

Additionally what soil mixtures do you prefer personally? I know many people here are exclusively hydro but I'm not ready to move in that direction just yet. Any advice?

Me never would go with hydro don't like water with my weed lol. I use FFOF just add a lil dolimite like mentioned above the lime buffers your soil so you dont have as many ph issues. Your idea seems ok but proll would not use peat moss though but perlite and lime go perfect with FFOF.

Are you still using FFOF? I'm going to browse around the forum for some amended growing mediums. This forum is effin' addicting and I just love seeing all of the different setups and gorgeous plants.

Yeah me to love learning I'm gonna post my current grow when I get my new laptop. I go some mini trees and 2 600 hps vertical with my environment perfect I love it (laughs to self)

After further research I think it does appear to follow the signs of phosphorus deficiency.... The tips are curling down a bit on the newer leaves and certainly effecting the older leaves at this point too, would you agree that this may be another sign of P deficiency? I'm still using the FF feeding schedule right now but I am mixing the solution just slightly weaker than the recommended dosage. I'm going to up the nutes, dial my PH meter and check the stem color closely for tomorrow's watering. I agree its immobile but I think it is working its way down the plant very slowly. The plant looking the worst is looking the best production wise at this point so I'm not awfully worried but it still stresses me. I also topped the soil off with a little dolomite lime as well thinking anything can help to get it straightened out. I honestly didn't expect that it might be phosphorus since they are getting it every other feeding but I guess maybe they just want more to make some stank buds.

Calibrated my PH and to my surprise it was off by 1.0. Shameful, I can't believe I let myself slip like that! Making the correction today and hoping they beef out some more.

I'll tell you I used striaght fox farm last grow had alot of def. Tell you what my girls love that will work get some high P bat quano mix it with first few inches of soil. I learned growing is not just about charts and feeding schedules give the girls what they want when they need it they will reward you.

Thanks Jdubb, this is my first round using a feeding schedule, I had great success with a one part veg and one part flower system with a few micronutrients but thought I would try this out. I'm definitely interested in ammending my soil to make it a more suitable medium though. I will probably stick with the FF line of nutes for one more round, I like the success I've had thus far yet it is unfortunate I've been set back in my yield due to the high PH levels I learn more every time! I got ridiculously lucky my first time and expected the results to be the same every time. Unfortunately they have not been but I know they will again.

Ahhh, deficiencies, gotcha. I am going to go with the perlite at the least but honestly I used exclusively Root Organics Buddha Bloom for my first grow with CalMag supplements in Happy Frog soil and I have not been able to match those results. I also used straight well water rested for 24 hours with no PH meter and I'll be damned if I can have that kind of luck again. I'm expecting the next round will match those results but I'm not overly confident.

Yeah you want to lock in what works and get better my first grow I did good. But since I have only gotten alot better my secret use common sense and don't grow like everyone else what fits their strains, growing environment etc. does not mean it will fit yours.

Well after calibrating my PH meter, adding a small amount of dolomite lime to the top of the soil and flushing each plant my runoff is still very low. Today I drenched with 7.0 solution and the runoff was 5.5-5.9. Is this normal? I have always assumed that my runoff should match that of my nutrient solution. Any suggestions? They are about finished and the fruit development is looking fairly good considering the issues I have encountered.

Well, another flowering cycle and yet more issues. I can't understand why I had early success without issues and the more I learn the more problems I encounter lol.

4 plants in flower total (2) Pure Power Plant at 25 days, (1) Pure Power Plant at 14 days and (1) White Widow at 14 days. Medium is 70% FFOF 30% Perlite with dolomite lime added.

The two PPP at 25 days started showing signs of sickness after my last watering. The younger (2) plants look great. All plants were transplanted the day flowering was initiated due to time constraints. I have been feeding 400-550 ppm water with grow Big 6-4-4 to keep my foliage healthy.

Drenched today with 420 ppm 10-30-20 + silica - PH 6.5 water and runoffs for sick plants were both 6.5 PH (calibrated today) and 1060-1070 ppm. Please find the attached pics. The whole plant appears to be ligher green almost turning a bit yellowish, bud development is slow but decent. The initial stretch doesn't appear to be there, the two younger plants have stretched the same if not more. I am wondering if it is sulfur def but also wondering how the hell that would happen. Thanks for looking.

What area did the leafs in the pic come from? Does the entire plant look the same?