-Soil medium: 4 parts perlite 1 part MiracleGro Sphagnum Peat Moss [0.05%, 0.02%, 0.04%](i know... MG=bad, all that's available in a city) 3 parts MiracleGro Organic Choice Soil [0.10%, 0.05%, 0.05%] -Indoor grow -Unknown strain but was from "heady outdoors nug"; all seeds should be from the same bag but are not clones. Out of 8 plants, 7 are female (lucky!), calyx development showed at day 37-39 -Plants are 46 days old -3x42watt 5100k CFLs, 2x30watt 'cool white' CFLs (186watts total) -Lights kept between 3-6in from tops -See 'chart' attachment for feeding schedule and runoff pH -Temps are between 75 and 80F (usually at 77-78) -Seedlings sown in solo-cups, transplanted to 1.5gal pots on day 17, transplanted to 3.25gal pots on day 44 -Definitely no bugs - have looked closely and with magnifying glass -Tap water pH is always around 9.2-9.3, after adding nutes pH is around 3.5-4.5 (depending on nute solution), and usually 1tbsp/gal of EarthJuice Natural Up is required to bring feeding solution pH back up to 6.8-6.9 (is this bad i.e. lead to too much salt in medium?) Same number (e.g. #4) means same plant: -Pic "#4.jpg" shows lower fan leaf. Is this an N deficiency? Other leaves are a faded light green so I feel like I haven't been feeding strong enough. -Pic "#4(1).jpg" shows spotting that's been happening for more than a week, originally effecting larger fan leaves but starting to appear at the tips of new growth starting at the top of the plant. Mn deficiency? -Pic "#1.jpg" shows the same type of spotting seen in pic "#4(1).jpg" on a larger fan leaf of another plant. Mn deficiency? Also, the tips of larger leaves have turned brown and curled since transplanting, though it's only been a day and I feel like that was happening already. I just increased feeding strength but they've seemed hungry so I feel like it shouldn't be nute burn... -Pic "#5.jpg" shows necrosis developing on the serrated edges of larger fan leaves. This is only afflicting one plant right now, though it was previously the healthiest looking one.
Looks like a nute burn. You have to keep in mind that MG soil contains time release nutes, so they are getting your dose AND the soil's time release dose. That's what is causing nute burn. Flush with plain water, let them dry out a bit, and start back adding nutes at 1/3 strength.
What symptoms make you think nute burn? I've been afraid of burning them and so feeding cautiously but leaves have been fading for at least two weeks now, and the fading showed up at least a week before spotting; I thought the fading suggested they weren't getting enough N? Also, if a flush is necessary, is it a bad idea to use pH 9.2 tap water adjusted to 7.0 with copious amounts of pH down? Or do I have to go ahead and buy a bunch of bottled water? If bottled water, does it matter whether it's "spring water" or "distilled water"? Distilled is probably better but hard to find for me so if it doesn't matter...
Like he said, your fertilizing it was too much since it had time release ferts already in there... You basically fed it twice the amount of nutes it needs, and now the plant is disposing of the unused nutes through the leaves.
I may have burned these babies a little with the last fertilizer dose but the fading and leaf spotting has been going on for weeks. When feeding at 1/3 strength the plants were fading from a healthy dark green to a lighter yellow-green, lower fan leaves were yellowing and dying, and new growth would develop as and remain a faded yellow-green. Wouldn't this mean they're hungry? The leaf spots were also progressing with only 1/3 strength feeding. Aren't they indicative of some kind of micronute disorder?
Yep, been checking runoff and nute solution pH's - see the attachment on original post, "chart.jpg" it's a spreadsheet of pHs over time. All plants have been getting the same treatment (or, I've tried to give them the same treatment) but pH's range from about 5.8 - 6.7. See "chart.jpg" for details.
OK 5.8 is a lil bad, should never be below 6.2 .. Whats the ppm/EC/TDS (any of them) of the run off ?
Yeah it had dipped down to 5.8 before i had a pH meter and again right after transplant (prolly the peat moss doin it). I don't have utensils to measure ppm/ec/tds, unfortunately... got any recommendations for cheap ppm meter (less than $100, preferably less than $50 if that's worthwhile)?
I did a flush last night, plants look perky this morning. I ran in to a little issue when watering my plants, though: drainage! They're in 3.25gal wastebaskets with drainage holes cut in the bottom. I water them in the sink but they're still draining after 20 mins. When suspended in a bucket allowed to drip free, they still drain for over a half hour, then continue to leak all over the floor of the closet grow area. I've got seven pots 8 1/2 x 11 in in a closet and I'm tired of mopping up a whole paper towel roll's worth of runoff from the floor... any ingenious ideas out there?!
You can get a digital EC meter on ebay for apx $50, Yes you do have a drainage problem, the pots should completely stop dripping after 10 mins. obviously if you move them some will drip but it should not need more than a few sheets to mop up. I don't know what to suggest as I've never had to deal with that situation. But you do need to keep an eye on the amount of water that's left in there before you water again, now you have a feel for the weight of the post when there soaked so just lift them up and as they get light water again. You could add a 3% peroxide solution to the water, that will give a lil more oxygen to the plant but it's not benifical to the micro life in the pot. I guess you wont make that soil choice again.