1st Time Grower - Care to lend a hand?

Hello everyone. Long time reader and finally registered on the site to post. I could use an opinion on what I'm seeing right now. I have been sprouting four seeds for 15 days under two 4' flouro tubes @38w each, 5000k spectrum. Plants were looking great. They grew to about 4" tall and developed three internodes. I then moved them in to a main grow space with two other plants which are 12" tall and having 8 internodes.

Here is the order that things happened in from there on out (six plants in room):

1. Switched bulb in main grow from 400W MH to 430W Hortilux HPS.
2. Plants were adjusted so canopy was 12-15" below enclosed light, air cooled. Ambient temperatures ~75F, Radiant head, relatively negligable.
3. After one or two days, all plants began to show signs of yellowing. Established plants only at new vegetation sites. New seedings... pretty much at tops of plants and working its way down.
4. Considered the possibility of low N, so fed all plants an appropriate nutrients (two different concentrations of Botanicare Pure Blend Pro). Also, mixed in just ever so little molasses to introduce a little Mg and Ca, since I am using RO.
5. Changed the light (again) to 1000W MH with new digital ballast. Kept plant canopies the same distance.
6. Established plants seem to be recovering. Yellowing is going down. Young plants are not really improving.
7. Today, moved young plants away from light, they are now 24" from source.

My thoughts are that the young plants were shocked going from low lumen flouros to HPS and then 1000W MH. I'm hoping that backing them off the light will help recover them. I just am not sure why when I introduced the HPS light that the established plants started yellowing so much. It is normal for this to occur? Also, will the young plants recover? Here are a couple photos of the plants as of today.

The picture up top is obviously an established plant.. you can see the yellowing at new growth sites. Here is what one of the smaller plants looks like:


Thanks in advance.

Much appreciated.

well my guess is a ph problem. If the ph is out of wack than the plants cannot take up nutrients. I mean seedlings should be able to take some intense light and unless the 400 was like right on top of it I don't think it would be light bleaching. Are you growing in a grow tent? i have seen some people have a problem with toxic vapers being emitted from some of them.

The room is a closet. The walls are covered in mylar and the floor in heavy plastic. Aaaah, heck with it... I'll take a picture... hold on...


This is the outside. The top of the door is the exhaust. The bottom is a passive intake.



This is just inside the door. Air intake through home made carbon filter.



Close up of filter. (It works good)


Under the light.


I'm only testing pH with papers. Always seems to be around 6. Using BioBizz Light soil. If I use tap water PPM reads 140... I'm going to switch to that since it's so low. I don't have a real good idea of the pH, I could test the run off, but the plants have been watered recently so probably best to wait a day or two.

Pipe Dream said:

well my guess is a ph problem. If the ph is out of wack than the plants cannot take up nutrients. I mean seedlings should be able to take some intense light and unless the 400 was like right on top of it I don't think it would be light bleaching. Are you growing in a grow tent? i have seen some people have a problem with toxic vapers being emitted from some of them.

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Ok i thought it was worth a shot as it seems pretty unusaul. I also use the ph paper and mine is at like 6.5 out of the tap..olive green. Good luck man you have quite the setup.

I decided to flush the small pots. We'll see if they recover or if I'm out $50 for seeds. I don't know what to do with the big plant. Probably just wait it out another watering cycle and see how it goes.

Pipe Dream said:

Ok i thought it was worth a shot as it seems pretty unusaul. I also use the ph paper and mine is at like 6.5 out of the tap..olive green. Good luck man you have quite the setup.

Click to expand...

Follow up... It seems that the radiant temperatures were probably waaaaaaay too high. It was only my second day using a 1000w bulb. I think I underappreciated how bright and hot these things are. I raised the lamp to 18" above the canopy and it seems like things might be improving. The plants are now raising their leaves to the light, so I hope I'm heading out of the woods. I did flush all the small pots with 1 gallon tap water and I flushed the main plant with 1.5 gallons of nutrient solution. If the little ones get some color back in them in a day or so, I'll feed 1/4 nutrients.

Follow Up: Two days since raising the light off the canopy. Color is beginning to return to leaves. I did flush all pots with 2x volume H20 and then followed up with a small amount of diuted nutrients. I have one plant right now that is in 12/12, so when that one visits the room each day, the reflector goes up and the 1000w hps goes in. Once that cycle is done, the reflector goes down and the 400w MH goes in and the little plants stay on for another 12 hours of blue light. Seems to be working. I did buy all the necessaries for a 6 pot DWC setup... when that arrives, I'll do a proper grow blog. I have 5 clones right now that are rooted and ready (one is a little sickly). I'm going to take four more off the plant thats in 12/12 from the bottom and get those in the cubes. The best clones will get a DWC pot. The other ones... mmmmm soil.