First grow, can't figure out the issue :/

Have been going through forum after forum trying to figure out whats going on, but with zero experience its hard to put my finger on whats happening :/ Im leaning towards phosphorous deficiency, but I can't be too sure. Any help would be incredibly appreciated!!

It started with the cotyledons, which wilted and fell off and now the first set of leaves are showing these darker spots on the outside of the leaves.

Strain is purple kush
2 weeks 4 days old

Started from seed
No nutrients have been used
Soil medium
Watered when the top inch of soil is bone dry
RO watered pH 6.8
Plant is 3 days from 3 weeks old.

First two pictures are of the same leaf (possible phosphorous deficiency?)
3 & 4 are of the other leaf (possible calcium deficiency?)

Last picture is of the rest of the plant

Your RO water is leaching the Calcium from the soil, so yeah, probably some CalMag with that RO from now on. Maybe a slightly lower pH too.

Depending on the soil, you may need nutrients, 3 weeks seems about when I start, if I'm taking it easy.

I bet if you start feeding and add CalMag, you'll be golden. Start with half strength and adjust from there. Don't overwater. pH to 6.3 or so, unless you're doing organic.

What nutrients will you be using?

Oh, and the cotyledons usually will just fall off anyway.

If your in decent soil it will buffer ph by itself so there's no need to be adjusting ph in the first place ....ph swing in soil is a good thing IMO it allows for nutrient uptake ....I'd stop adjusting ph since your in soil and start some light feeding as cal mag like mentioned above .....be sure you don't overwater ......good luck

KevB. said:

Have been going through forum after forum trying to figure out whats going on, but with zero experience its hard to put my finger on whats happening :/ Im leaning towards phosphorous deficiency, but I can't be too sure. Any help would be incredibly appreciated!!

It started with the cotyledons, which wilted and fell off and now the first set of leaves are showing these darker spots on the outside of the leaves.

Strain is purple kush
2 weeks 4 days old

Started from seed
No nutrients have been used
Soil medium
Watered when the top inch of soil is bone dry
RO watered pH 6.8
Plant is 3 days from 3 weeks old.

First two pictures are of the same leaf (possible phosphorous deficiency?)
3 & 4 are of the other leaf (possible calcium deficiency?)

Last picture is of the rest of the plant

View attachment 3744046 View attachment 3744047 View attachment 3744048 View attachment 3744049 View attachment 3744051

Click to expand...

My suggestion is to chill, that plant is fine, sometimes lower leaves will yellow as the plant no longer needs them. The plant will likely drop those leaves all togeather in the days ahead. Keep calm, shes fine.

purplehays1 said:

My suggestion is to chill, that plant is fine, sometimes lower leaves will yellow as the plant no longer needs them. The plant will likely drop those leaves all togeather in the days ahead. Keep calm, shes fine.

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Dude, I have to disagree. That is an unhealthy plant. Lower leaves start yellowing near the end of flower, not early to mid veg. The vast majority of my leaves remain on the plant through flower, losing only the ones getting little light.

KevB. said:

Have been going through forum after forum trying to figure out whats going on, but with zero experience its hard to put my finger on whats happening :/ Im leaning towards phosphorous deficiency, but I can't be too sure. Any help would be incredibly appreciated!!

It started with the cotyledons, which wilted and fell off and now the first set of leaves are showing these darker spots on the outside of the leaves.

Strain is purple kush
2 weeks 4 days old

Started from seed
No nutrients have been used
Soil medium
Watered when the top inch of soil is bone dry
RO watered pH 6.8
Plant is 3 days from 3 weeks old.

First two pictures are of the same leaf (possible phosphorous deficiency?)
3 & 4 are of the other leaf (possible calcium deficiency?)

Last picture is of the rest of the plant

View attachment 3744046 View attachment 3744047 View attachment 3744048 View attachment 3744049 View attachment 3744051

Click to expand...

Time to up pot and use soil such as Happy Frog and Ocean Forrest mixed 50/50

What's wrong with using tap water? RO is for hydro, in my opinion. Tap water is fine for your yard and trees, right? Cannabis is not some alien plant, it is more tolerant than a lot of the stuff growing in your yard. Use tap water, and don't even adjust the pH if it is between 6.5 and 7.5. Probably enough calcium in it you can skip that supplement. Look up your municipal water data to find out what is in it, it should be publicly available by law in most jurisdictions. I see more problems from too much calcium and magnesium in soil more often than I see problems from too little. Re-pot, use tap water, and feed very lightly every other watering until you get a feel for how your plants respond. That's my advice, keep it simple.

TrimothyLeary said:

Your RO water is leaching the Calcium from the soil, so yeah, probably some CalMag with that RO from now on. Maybe a slightly lower pH too.

Depending on the soil, you may need nutrients, 3 weeks seems about when I start, if I'm taking it easy.

I bet if you start feeding and add CalMag, you'll be golden. Start with half strength and adjust from there. Don't overwater. pH to 6.3 or so, unless you're doing organic.

What nutrients will you be using?

Oh, and the cotyledons usually will just fall off anyway.

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Thank you! I have some Advanced Nutrients CalMag that I wasn't sure I should start using yet, but you've answered that for me too. AN wasn't my first choice, but I had bought my lights off of kijiji and the guy gave me a 32L tub full of 1L bottles of their nutes for free.

As for the soil it is in now, Im unaware of what it is as my girlfriends dad gifted the seedling the day it broke through the soil. I live in Alberta Canada, so I have no access to Fox Farms or Happy Frog, or really anything other than generic brands of soil and ferts.

I do have some Pro-Mix potting soil i plan to add:

1 part Pro-mix potting soil
1 part Earth worm castings
1 part perlite

And then amending with kelp meal, alfalfa meal, crab meal.

Let me know if i should drop any of those items and/or add anything else!

And thank you for the knowledge, much appreciated

Indacouch said:

If your in decent soil it will buffer ph by itself so there's no need to be adjusting ph in the first place ....ph swing in soil is a good thing IMO it allows for nutrient uptake ....I'd stop adjusting ph since your in soil and start some light feeding as cal mag like mentioned above .....be sure you don't overwater ......good luck

Click to expand...

Unfortunately, I don't think the soil I'm currently in is to great. But I'm thinking I'm about ready for a transplant soon? Or should I give it another week? Not sure on my end haha.

Okay awesome, i'll leave the pH gear sit for now then.

Yeah the whole watering thing makes me sweat if I think about it to much haha.

Thank you for the info! Will definitely keep what you said about pH swing fresh in my mind.

fandango said:

Time to up pot and use soil such as Happy Frog and Ocean Forrest mixed 50/50

Click to expand...

Unfortunately the only access I have to those are $40 12 quart bags on amazon :/

Do you think a mix of the following would suffice?

1 Pat pro-mix potting soil
1 Part Earth worm castings
1 Part Perlite

And amending with a few cups total of kelp meal, alfalfa meal and crab meal.

Michael Huntherz said:

What's wrong with using tap water? RO is for hydro, in my opinion. Tap water is fine for your yard and trees, right? Cannabis is not some alien plant, it is more tolerant than a lot of the stuff growing in your yard. Use tap water, and don't even adjust the pH if it is between 6.5 and 7.5. Probably enough calcium in it you can skip that supplement. Look up your municipal water data to find out what is in it, it should be publicly available by law in most jurisdictions. I see more problems from too much calcium and magnesium in soil more often than I see problems from too little. Re-pot, use tap water, and feed very lightly every other watering until you get a feel for how your plants respond. That's my advice, keep it simple.

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I believe I asked myself why I wasn't just using the tap water, but had zero answer for myself haha. My cities water data states we have 35-64 mg/L of Calcium. What are your thoughts on that as I really have no idea if thats too little, too much, or just right.

Thanks for the info!!

That's plenty. Check your chlorine percentages, chances they are pretty low. If you are comfortable posting your city or a screenshot of the data I can be more help, more quickly

What are the total dissolved solids or parts per million a.k.a. PPM?

Michael Huntherz said:

That's plenty. Check your chlorine percentages, chances they are pretty low. If you are comfortable posting your city or a screenshot of the data I can be more help, more quickly

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http://www.calgary.ca/UEP/Water/Pages/Drinking-water/Annual-water-quality-report/Water-Quality-Parameters.aspx

Hopefully thats enough info for you!
Thank you again Michael

Greetings. If I use RO or even Filtered water I am in the ca:mg bottle hard, my plants like tap water best. I tend to think people get anal with the RO water just because they like variable free slate to work from. Im happy with a 0.4 starting point.

Just give it some regular water for a couple waters, make sure your letting it dry out before watering. Your soil should be fine for the nutrients for such a small plant, it most likely does not need much water at all right now. Add nutes after one or two more regular waters. GH micro bloom and grow. Bat guano bud swell, and Hyrbix molasses for plants. Use a spray I like onyx organic natural pm and bug protector. Anyhow just make sure that it drys out well before watering again, you want the roots to be reaching out for the water, ever pushing though making new ground, in turn making your baby bigger and stronger.

I wouldn't worry to much your plant will start to gain a lot more vegetation to replace that.

good bit of advice i think is once you change something dont expect the busted up leaves to get better EVER. damaged leaves stay like that. you have to wait and see if NEW grown leaves show up with the same problem to know if whatever it is you changed worked.

Michael Huntherz said:

What's wrong with using tap water? RO is for hydro, in my opinion. Tap water is fine for your yard and trees, right? Cannabis is not some alien plant, it is more tolerant than a lot of the stuff growing in your yard. Use tap water, and don't even adjust the pH if it is between 6.5 and 7.5. Probably enough calcium in it you can skip that supplement. Look up your municipal water data to find out what is in it, it should be publicly available by law in most jurisdictions. I see more problems from too much calcium and magnesium in soil more often than I see problems from too little. Re-pot, use tap water, and feed very lightly every other watering until you get a feel for how your plants respond. That's my advice, keep it simple.

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if u have decent tap water its not a big deal. But i live in So Cal and have 500 PPM water with tons of chlorine in it, not good for the girlies.

chlorine isnt bad. you can intentionally add the stuff for sterile grows instead of using bennies. taps fine, some strains may need some help in another area. if you ever grow multiple strains you might get a chance to see side by side how one strain is having issues while the other is growing out of control in the same dwc tote.

KevB. said:

Unfortunately the only access I have to those are $40 12 quart bags on amazon :/

Do you think a mix of the following would suffice?

1 Pat pro-mix potting soil
1 Part Earth worm castings
1 Part Perlite

And amending with a few cups total of kelp meal, alfalfa meal and crab meal.

Click to expand...

Sure would work,except use 1 bag of pro-mix-1/4 bag Perlite-4 cups worm castings...some thing like that ratio.