Is she ready for nutes?

Hello,

21 days old
2 Autoflower lemon haze
4 60w 6500k cfl
4 23w 65000k cfl
4 gal pot Fox farms ocean forrest and 30% perlite

Time to give them nutes? Any ideas of the deficiency in the photos?

Thank you

I would just give these plants a dose of cal mag & save your nutrients until they are needed. These plants appear quite healthy otherwise- your ffof soil is stout enough & should carry them through most of flowering if you use non-chlorinated water. They seem to be older than 21 days from seed...more like 21st day of flowering ... do you run your autos on 12/12?

start with a quarter strength solution and gradually increase. GL

Richard Drysift said:

I would just give these plants a dose of cal mag & save your nutrients until they are needed. These plants appear quite healthy otherwise- your ffof soil is stout enough & should carry them through most of flowering if you use non-chlorinated water. They seem to be older than 21 days from seed...more like 21st day of flowering ... do you run your autos on 12/12?

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nope they sprouted on the 5th. i've been running 24 hours and they love it. So deff a cal-mag deficiency? Thanks for the reply

Wow those sure started budding out w/ the quickness...Yeah pretty sure the little rust spots are start of a cal mag def- FFOF notoriously contains very little. I recycle my spent ocean forest soil & every time I "cook" & recharge it up for another run I add back some garden gypsum and dolomite lime which helps reduce the need to use liquid cal mag- though I still gotta add some in mid to late flowering when they really need a lot. Calcium and magnesium among other macros sort of work together with the microbial life which help your plants uptake NPK from the soil. I also recommend using general organics cal mag if you can; it's the only brand I know of that is truly safe for organic living soil grows.

Richard Drysift said:

Wow those sure started budding out w/ the quickness...Yeah pretty sure the little rust spots are start of a cal mag def- FFOF notoriously contains very little. I recycle my spent ocean forest soil & every time I "cook" & recharge it up for another run I add back some garden gypsum and dolomite lime which helps reduce the need to use liquid cal mag- though I still gotta add some in mid to late flowering when they really need a lot. Calcium and magnesium among other macros sort of work together with the microbial life which help your plants uptake NPK from the soil. I also recommend using general organics cal mag if you can; it's the only brand I know of that is truly safe for organic living soil grows.

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Yeah all my nutes are GH How much calimagic 3ml per gal?

Yes Id give them 1/4 strength grow nutrients now, and also add cal mag at half strength (I use distilled water). Definitley start that regimen every other plain watering.

GH has an organic offshoot line called general organics - calmagic is synthetic but whatever, I would give them slightly less what is recommended by the feed chart. A ppm or EC meter is the most accurate way to mix up yer nutes - I'd mix in calmag until the meter says it had about 250ppm...something like 1/4 tsp per gal.

See, IMO cutting FFOF with 30% perlite is OD.

When you do that you're killing the soils buffering capacity; which would otherwise be higher. Perlite has no cation exchange capacity. It doesn't provide any nutrients but more importantly it doesn't "hold onto" them either. CEC is the characteristic of soil that both prevents nutrient cations (+) from washing away, and allows it to resist sudden changes in pH.

I used to mix coir and limestone into OF instead. I'd also recommend general organics if you don't have dechlorinated tap water with a good mineral content.

Nullis said:

See, IMO cutting FFOF with 30% perlite is OD.

When you do that you're killing the soils buffering capacity; which would otherwise be higher. Perlite has no cation exchange capacity. It doesn't provide any nutrients but more importantly it doesn't "hold onto" them either. CEC is the characteristic of soil that both prevents nutrient cations (+) from washing away, and allows it to resist sudden changes in pH.

I used to mix coir and limestone into OF instead. I'd also recommend general organics if you don't have dechlorinated tap water with a good mineral content.

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Excuse my ignorance but what is OD? And CEC? I usually add extra perlite to my mix, well maybe not 30% more like a handful or 2 per cu ft. I have read that the micro beasties like to live inside the little nooks & crannies that in the perlite- don't see how it's a bad thing

Overdose, overkill, more than what is necessary. Materials like compost, humus, earthworm castings, clay, coco coir, sphagnum and vermiculite have measurable Cation Exchange Capacity. The particles are small enough to possess a high degree of electronegativity and attract ions via exchange sites. Cations have a + charge and include one form of nitrogen (ammonium), calcium, magnesium, potassium, iron, zinc, copper, etc. The exchange sites hold nutrient cations like a magnet, so they won't wash away (leach) but remain plant available.

Sand, rockwool and perlite are virtually devoid of CEC. Not great substrates for microbes either, which would prefer to live on organic matter they can break down or do something with. Too much perlite means less room for nutrients and notable consequences will be more frequent feeding and watering.

I see what you are saying but let's say you added a lot of perlite to your mix couldnt you just add in some coco or other type of neutral medium or maybe more worm castings to offset it?

Yes. Compost, castings and humus are dense materials though. Not quite as dense as clay but can still make a potting mix heavy. I try to keep compost/castings at 20-25% total volume, so I calculate how much I'm going to add of what before I start mixing.

A handful of perlite per cubic ft is nothing compared to 30% of the total mix for a potting soil that already has it.