Troubleshooting some Growing Seedlings Issues

I am starting many of my seedlings indoors under grow lights as I don’t have enough natural light. All are doing relatively well but I do have a few questions.

Some of the seedlings have a leaf or two that appears very pale. As in almost white tinged. Could this mean the lights are too strong for these fellas? I’ll post a pic below.

Also some of my lemon balm seems to have red tinged leaves. Not sure if that is normal too?

Last but not least, some of my catnip leaves has developed black spots on the leaves and wondering what would cause this and what this may be. They were not apparent last night but seem to have developed overnight. They are on the upperside of the leave and the leaves are dry. The seedlings are quite large so I switched over 24hrs ago to pot watering versus misting as they were drying out fairly quickly in between mistings. However, I am beginning to wonder if the pot watering is just too much water for them and this is what caused it? OR Is this some type of bacteria or fungus or mold? Any recommendations and tips to troubleshoot would be greatly appreciated! I snipped off a few of the problem leaves in case it was something that could potentially spread.

TIA (pictures were taken just after their morning watering))

Do you have good air circulation around your seedlings? Are you fertilizing occasionally with an all-purpose liquid fertilizer? What are you using for a light source?
In general, my approach to growing seedlings of any kind under artificial light is to use sets of four 48" fluorescent shop lights (cool white/warm white doesn't seem to make much of a difference IMHO) hanging on chains that can be raised as the plants grow. Keep the lights as close as possible to the plants without touching the foliage. A germination mat is very helpful to get seeds going. Use a good soil mix. Set the lights on a timer for about 16 hours a day. You can also use a small fan set to the same timer with a power strip. Don't overwater!
The first 2 photos look like some nutrient deficiency. Not sure about the black spots on the 3rd photo, but could be fungal, which is why I asked about air circulation.
Best of luck!

Hello Jegtrio,

" Some of the seedlings have a leaf or two that appears very pale. As in almost white tinged. Could this mean the lights are too strong for these fellas? "

Outdoors in the sun has a light level of 5000 foot candles or more. Indoor lighting rarely runs over 1000 foot candles, so your lights are not too strong, unless the bulbs are so close to the seedlings that their heat is too much, and that would brown the leaves. The loss of leaf color is probably a sign of a nutrient deficiency. You might want to add some soluble nutrients to the water you are watering them with. I like the Sun Bulb products for Orchids, because they are urea free.

https://www.amazon.com/Sun-Bulb-Company-8303-16-Ounce/dp/B004Z6JOXY/ref=pd_bxgy_2/138-1435169-1574224?_encoding=UTF8&pd_rd_i=B004Z6JOXY&pd_rd_r=dc162665-5e67-4b27-abbc-06849fdca5ba&pd_rd_w=Kolf0&pd_rd_wg=sIYWG&pf_rd_p=4e3f7fc3-00c8-46a6-a4db-8457e6319578&pf_rd_r=W7A5KXJGGRBT3GGF2WTP&psc=1&refRID=W7A5KXJGGRBT3GGF2WTP

Urea is a nitrogen source that depends upon microbes in the soil to break it down into usable ammonium and nitrate ions. Potting mixes frequently don't have any or enough of those microbes to make the nitrogen in urea available to plants. So using urea-free nutrients is advisable for indoor growing. This book is one of the few that is up-to-date for indoor gardening.

https://www.amazon.com/Gardening-Under-Lights-Complete-Growers/dp/1604697954/ref=sr_1_3?dchild=1&keywords=gardening+indoors&qid=1591202847&s=books&sr=1-3

I started some zinnia seedlings indoors for setting out into outdoors locations, and used that Sun Bulb product on them. My indoor growing medium is Premier Pro-Mix BX.

ZM (Not associated with any product or vendor mentioned or linked)

This message was edited Jun 3, 2020 12:10 PM