Onyx Autoflower
49 days old
FFOF soil
FF nutes at 1/4 strength
45% RH
71 degrees F
600W LED
I have not taken run off PH however every-time I water and feed I vary the PH between ~6.2 and ~6.5
every time I grow an auto it gets these big orange rust spots. there is purple around a lot of the edges of the leaves and around the rust spots as well. Tried to get the best pics I could. Is this a nutrient deficiency or something else? I feed fox farm about every other watering at around 1/4 strength or so. This girl seems to be much more sensitive to nutrients that Plants I have grown in the past so I have kept it low. What do you guys think is going on?
Phosphorus deficiency with possible calcium deficiency, they go hand in hand. Are you about 2-3 weeks of flower? Get your run off ph . That will tell you if you have a lockout situation going on
Yea about 2 or so weeks into flower. Whats the best way to get run off PH? SHould I just water it until it starts coming out the pot, collect, and test PH?
I agree. You should be deep into your flowering nutes and the FFOF is likely exhausted. You really need to be doing runoff TDS to see condition of soil.
If youre using fox farm nutes, you should also follow their flushing schedule.
Id start with a slurry test. Just to be accurate.
Not knowing your runoff ppms, I’d also suggest flushing, then a light feed with added calcium.
A few days later I’d do a slurry test again. If it falls below pH 6.0 I’d top dress with a little dolomite lime.
That’s best. But you need to up your numbers and once again harping on a TDS meter: they’re $15 on Amazon and are worth every penny. You can see in the runoff how depleted your soil is and make adjustments to your input strength. It’s easy once you figure it out.
EC times 500 = ppm/500 scale. In other words an EC of 1 = 500 ppm. So if you had an EC of 2.310 would be around 1150 ppm. Just different ways of measuring TDS.
That’s not a bad number for where you are.
I can only think you had a PH departure that caused a deficiency or one feeding was way high.
I have Ph’d all ofmy feedings and my meter is calibrated and accurate. I usually feed around 6.2-6.4ph. I flushed it last night with 6.9ph water. From here should I just feed her with higher PH water/nute solution? The PH of the soil is 5.5 and I imagine I would want to raise that correct? I was thinking let it dry out a bit and then feed a light feed as was suggested?
I would suggest when you water to have the PH at 7.0 or so and when you feed (water nutrients mix) do the same. I would also think that you would want to use more feed than the 1/4 your using…bigger plants need more.
Each water or feed use enough to get some run off and check to see which way it’s trending and adjust input PH accordingly. Once in range then 6.5 is a sweet spot.
That chart is good! You can see that if your ph is 5.7 tge big 3 and a few other needed foods are not as available. That is what everyone calls a nutrient deficiency. However, the nutrients may actually be there in spades! Just locked out! On the other hand because the plant cant access the material it builds up and creates a toxicity as well as a lock out. So when you flush, you are also washing out potentially high levels of materials that built up over time because thenplant could not access them. As you can see by the chart, this is the main advantage of pure liquid hydro. You can increase or decrease nutrien availability by adjusting ph up or down very easily. In soil it is not so intuitive or easy. Good luck and all will be fine as long as you do as the other guys say… OR ELSE!
