Help w/ Yellow Spots?

Growing under fluorescent lighting at 18/6 (2 Ecolux F40 plant/aquarium bulbs from Walmart). Plant is about 7 weeks old and has started to get yellow spots on the upper leaves. Also the edges are starting to curl under a bit and maybe some twisting of the leaves. Also noticed that there is a section of the stem that has a slight reddish color to it. Growth has slowed. Using Vigoro 12-10-5 fertalizer.

I am guessing that this may be a nutrient deficenty of some sort, possibly potassium or magnesium?

I just read about PHing the water... just checked mine with some pool strips and PH is at about 8.5. I know it should be about 7, so I'm off to get some PH down tommorow.

Should I just keep doing what I've been doing with the water lowered to a 7 and see if things change or what else should I do?

time to repot and get stronger lights too, try flushing your soil with 3 of those dixie cups of pure water first. Those are tiny for 7 weeks.

When you say flush with 3 of the dixie cups, do I do that all in the same day and then move it to the bigger pot? Sorry, this is my first grow and I'm still learning.

MoonGrower said:

When you say flush with 3 of the dixie cups, do I do that all in the same day and then move it to the bigger pot? Sorry, this is my first grow and I'm still learning.

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that's right take your time, use room temperature water, water, let it sit a few minutes to dissolve the salts then water again to flush that out, repeat till it's all used up.

I assume that the fertilizer (Vigoro 12-10-5 pellets) is fine to add to the soil of the bigger pot? Also, should I mix it in with the soil or just do a layer on the bottom and one layer on the top? Oh, and thanks so much for the help!

MoonGrower said:

I assume that the fertilizer (Vigoro 12-10-5 pellets) is fine to add to the soil of the bigger pot? Also, should I mix it in with the soil or just do a layer on the bottom and one layer on the top? Oh, and thanks so much for the help!

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Sorry i didn't know that was pelleted food. DO NOT USE IT AGAIN (you can't control the rate of release properly). Use a soluble fertilizer like Miracle Grow or Peter's etc 20-20-20 1/4 teaspoon to a gallon of water. Feed one cup of solution per gallon of soil after you've watered, every watering. Water to the point of runoff to flush out any salts left from the previous feeding.

frmrboi said:

Sorry i didn't know that was pelleted food. DO NOT USE IT AGAIN (you can't control the rate of release properly). Use a soluble fertilizer like Miracle Grow or Peter's etc 20-20-20 1/4 teaspoon to a gallon of water. Feed one cup of solution per gallon of soil after you've watered, every watering. Water to the point of runoff to flush out any salts left from the previous feeding.

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Thanks again... I flushed and moved them to bigger pots and am using Miracle Grow all purpose and I bought some acid regulator to balance out the PH. The plants seem to be growing better now and I just went to 12/12 to start the flowering. Both plants had about 5 nodes.

My question now is that I'm seeing yellow tips - which I assume is most likely due to over fertilization so I'm backing off on that some (it's definantly not heat since they are under fluros and the temp is about 75-76). So is the yellow tips indeed over fert?

My second question - the pots they are now in are 3 gallon ones I got at Walmart. They are supposedly "Self Watering Plant Spa" pots ($9.97) that have a reservoir at the bottom. The sticker says only water from the top for the first week and then just keep filling the res. It also says the base is ventilated to promote drainage and aeration. Will this work? Supposedly it prevents over watering which I have been concerned about as this is my first grow and I'm trying not to be over anxious - although it's hard. Right now I'm just using that and adding the nutted water from the top. Should I perhaps be adding the nutted water directly to the reservoir instead?

Also if the reservoir is a good deal on watering - I was thinking perhaps of getting a cheap aquarium pump and some air stones to keep the water moving... worth the effort?

Finally, I was thinking... even if both my plants turn out to be males (especially since originally I had a high PH) of going ahead and raising them into adulthood just for the experience so next time I might do even better, that and the fact they are just cool looking plants. What do you think?

I don't have any time to spare now for detailed replies (maybe tomorrow). I don't think the aeration is of any benefit but who knows, you may be on to something.

MoonGrower said:

My question now is that I'm seeing yellow tips - which I assume is most likely due to over fertilization so I'm backing off on that some (it's definantly not heat since they are under fluros and the temp is about 75-76). So is the yellow tips indeed over fert?

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Miracle Grow is pre fertilized (heavily) with time released fertilizer, any additional nutrients will overload the plant. Excessive watering will increase the rate of the time released nutrients. Mixing in 50% perlite will buffer the effect and is recommended by users of MG soil.
I would not add any nutrients to the reservoir.
Growing on males is an option certainly, there is no substitute for experience. You might want to practice cloning with the side shoots. Males contain a bit of THC too as does the pollen.

Actually, I'm using some organic soil - forget the name. The MG is the powdered blue stuff that I mix with water. Used 1/2 tsp for a gallon of water, and then balanced out the PH of the mixture.

I agree, repotting is most important and lighting is also most important. Try some cfl bulbs for this grow...

MoonGrower said:

Actually, I'm using some organic soil - forget the name. The MG is the powdered blue stuff that I mix with water. Used 1/2 tsp for a gallon of water, and then balanced out the PH of the mixture.

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OK, got the picture. I don't know what your problem is then for the burnt tips.

Found this table which seems to say it was over fert.

http://www.weedfarmer.com/cannabis/tables_guide.php

MoonGrower said:

My second question - the pots they are now in are 3 gallon ones I got at Walmart. They are supposedly "Self Watering Plant Spa" pots ($9.97) that have a reservoir at the bottom. The sticker says only water from the top for the first week and then just keep filling the res. It also says the base is ventilated to promote drainage and aeration. Will this work? Supposedly it prevents over watering which I have been concerned about as this is my first grow and I'm trying not to be over anxious - although it's hard. Right now I'm just using that and adding the nutted water from the top. Should I perhaps be adding the nutted water directly to the reservoir instead?

Also if the reservoir is a good deal on watering - I was thinking perhaps of getting a cheap aquarium pump and some air stones to keep the water moving... worth the effort?

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I second this question. I have those Plant-Spa pots as well, want to know if they actually last 2 weeks without having to water them. Last time I watered through the reservoir, my plants sucked up all the water in a day..-_-