First time grower. Seedling yellowing

I am growing a photoperiod. The seed sprouted 5 days ago. My soil is miracle grow that I sifted fine (I know it’s not ideal but it’s what I had). Humidity has stayed at 60% because I was told by the grower to keep humidity lower because this strain is susceptible to mold. Temperature is 80. The ph of the soil is 6.9 (maybe a little high?). The container is a red solo cup that has about 50 holes in the bottom and all the way up the sides. Im letting the soil get mostly dry between watering and right now the top is dry but 1/4 inch down is moist. The first 3 days the seedling was stretching really tall and I had it in miracle grow that wasn’t sifted and I was top watering. The light was 300 ppfd according to a phone app and the ppfd map included with the light. I tried 3 phone apps that all agreed exactly. The light is on 16 8 4am to 8pm. I transplanted the stretching seedling to plant it deeper and change the soil to a fine sifted one. I also increased the light to 500ppfd and started bottom watering. I know that’s a lot of changes at once and was a bad idea, but I was high.

This was last night

This is this morning

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New growth will always be a lighter shade of green. Darker green will fill in when chlorophyll catches up with the new growth. What you are observing is normal.

You are likely headed for problems. The issue with MG products is that they have time-release nutes that nuke your plant with nitrogen and submarine your pH each time you water. Scotts/MG/Vigoro are all make by the same company and they are historically known to make their product cannabis un-friendly on purpose. I would get your plant out of the MG as soon as you can. Cannabis and MG are not compatible.

Welcome to the forum.


Thanks, im switching to happy frog soon. I soaked the mg for an hour to try and remove some of the excess nutes.


It’s not going to help by much. It takes time for those nitrogen pellets to dissolve. MG isn’t properly buffered for cannabis to begin with, which is a major issue with it.

Happy Frog is a good choice.


All pelets and stuff were sifted out. Its very fine with nothing larger than a grain of sand. I sifted it with a kitchen sifter. Will it hurt my plant to wait 2 weeks before transplant? I dont want to stress it

You’ll have to see how it goes. Some plants will do fine, others won’t.

MG products are still not properly pH buffered for cannabis.

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Is there a way for me to buffer it myself? Or should i just wait and see then switch to happy frog?

I’d switch as soon as you can.

This could be a gamble, but…

With happy frog ready with a 1.5" diameter hole about three inches deep, ready for the seedling, place the entire cup with seedling in PH’d water until it’s a loose slurry. Submerged to the top of the cup. You would be trying to do a transplant of bare root. The MG soil so loose you can VERY gently pull the seedling out. Or pull the whole thing out and rinse most of the soil off… GENTLY.

How extreme you go is up to you, just try to get as much MG off the roots as you can without damaging the VERY fragile roots.

Hold the seedling in the hole in the happy frog and water the soils to fill in the hole around the roots. A tiny gentle wiggling to help keep the roots separated a bit. Make sure the new container has enough holes to drain well.

I’ve done this with other seedling but never cannabis, wait for some of these guru’s give the idea a thumbs up. While you wait youtube " bare root tomato seedling transplant "

Something like this. Don’t pull leaves, but plant it deep, all the way up to just under the “round” leaves. In the vid she says pull leave you don’t need them, leave them, the plant will eat those.


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Thanks for the idea. I think im just going to keep my ph at 6.3 when watering and measure the runoff to make sure its not too far off of 6.3. Ill switch to happy frog in a week or two

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This being your first grow when you go to transplant don’t try to rinse it off. You removed the pellets. The soil will not harm the happy frog and will after a few weeks no longer be a part of the equation. Root will be in the happy frog. One solo cup of MG isn’t going to ruin your grow. Just refrain from using MG in the future and you will be fine.

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I found the issue. It was over watering. The leaves curled down in the next few days. Just so anyone finding this forum in the future know