Hey everyone, wondering why my plants have these spots and faded parts

[Remystemple]

Growing in coco / perlite. using fox farm trio at 1/2 strength with calmag plus and watering 2 times a day with runoff. I feel like it's a pH issue or a calcium issue or they're related. that's my best guess from what i've read online so far.

2 days ago i started giving only grow big 2ml / gallon. and cal mag plus at 2ml / gallon.

any help or advice would be awesome. i'd like my first grow to go well.

 

[Remystemple]

Also it looks way worse under the led lighting.

 

[Remystemple]

coco with about 30% perlite. I'm using the fox farm trio with cal mag plus. all the nutrients are at half and watering every day or twice if i can. After reading I can only guess this is a pH issue. 5.8 - 6.3 after some reading i've been trying to keep the pH at 6.1 or 6.2 in hopes that it's a calcium problem due to too low pH. but was also wondering if it's fungus. I don't think it's possible due to my low humidity 25% temps are at about 22c.

Thanks for any help.

 

[pontiacman]

Look like ph. Ph and temperature is every thing....

 

[TorturedSoul]

Be me, I'd check for bugs (especially on the undersides of the leaves at first light before the fans have a chance to disturb the plants), lower the nitrogen content of your nutrient regime, and maybe hit 'em with a little Epsom salt for a magnesium boost. In addition to the amounts, the ratio of calcium to magnesium is important, and I'd try raising just the Mg before adding even more of your (combined) Ca/Mg supplement.

But, again, that's just me.

EDIT: And, yeah, that RH is low.

 

[Remystemple]

I'll give that a shot. sure hoping it's not bugs. also kinda wishing i went with a soil grow for my first try. I'm gonna look for a decent humidifier asap as well. I was getting the RH up to almost 40% with trays of water and wet towels hanging but it was just too much clutter in the grow room lol.

Thanks a lot for the help.

 

[TorturedSoul]

Oh, oops, that's a hydroponic grow? I aim for a 5.8 pH target, but don't get anal about it; might go 5.7 and let it drift up to 5.9 as the plant consumes phosphorous, then drop it back down, that kind of thing. But, basically, 5.8 for hydroponics.

 

[Virgin Ground]

This should help. Ca is available at 5.8 and below for hydro/ passive hydro. Allow for some drift. Let her eat at the entire buffet, not just a section. If that makes sense to you.

 

[Remystemple]

so the pH will rise as the plant takes up the nutes? that would make sense. amazing charts. Thanks so much.

Also i'm left wondering why is it that there's massive info online that says 5.8 - 6.3 is best for hydro. this is obviously not the case. that's a lot of misinformation out there.

 

[TorturedSoul]

so the pH will rise as the plant takes up the nutes

Kind of depends on which specific element(s) is/are being consumed. In the case of phosphorous... If you look on the label of many (most?) bottles of pH Down products, you'll find that they're mostly some form of phosphorous - because it lowers pH, and it's something that plants need anyway. The... ah... other end of that is that, as the plant consumes the phosphorous from one's reservoir, this reduction of phosphorous content causes the pH to rise.

Other elements cause the pH to rise. Silicon, for example, is alkaline and does that thing. As a matter of fact, if a real idiot someone decides to supplement the nutrients in their reservoir with a silicon product, doesn't pay attention and dumps way too much in, then decides that they'll just drain/rinse/refill the reservoir in the morning, well... he just might awaken to find that his plant is dead and 99% of its leaves are now laying on the grow room floor. Or, you know... So I have read .

 

[Remystemple]

alright! i feel like i'm finally getting a grasp on this. so my pH is high right now, 6.2 last time i checked the runoff. i want to lower it down to 5.8 or 5.7. how much and how fast can i drop it down without shocking the girls? Also is it true coco grows should be watered more than once per day? to flush and such?. I've read that you're not supposed to give fresh water because they get used to nutes.
So if i'm to water twice a day with nutes in every watering, how strong should they be? I've been doing half but thinking it's still too much nutrients for that much watering.
And would RO water do anything bad? because i switched to it about a week and a half ago. started seeing the problems shortly after. switched back to tap water that's been sitting out at least 48 hours.

 

[Remystemple]

This should help. Ca is available at 5.8 and below for hydro/ passive hydro. Allow for some drift. Let her eat at the entire buffet, not just a section. If that makes sense to you.

I was going by this chart here. the 2 don't match up in all areas.