Please help me with 2 week old northern light baby issues...

Hey Guys,

Can anyone advise me? I'm not sure what I've done wrong. A couple of these two week old northern light seedlings are showing issues, the others are OK. They're all in the same environment with same nutes, etc. I'm not sure why some are ok, but others not?

At the moment I'm hand watering every 4 days (it's definitely not over watering) until they are moved to my new grow room in a proper controlled environment and put in to my new drain to waste system. They'll sit on top of some 8" big mama cubes I have all ready. I think I will move them in about 2-3 days when the room is complete.

Currently the environment isn't the best - RH is 50% and Temp is 26 degrees C. The new grow room is fully controlled, so they'll go straight in to Rh 75% / 28% C Temp / 1000ppm C02.

I'm using RO water add adding Calmag to bring EC to 0.4 / 200ppm(500) then adding 100ppm(500) of Hesi veg nutes to bring total EC to 0.6. pH is 5.8.

They're under an SK400+ LED, 3 feet away, PAR reading is 200.

It looks like a nute issue to me, is it possible they're not getting enough? I'm trying to be careful not to over feed or burn them.

Any advice would be appreciated.

Thanks,
J

Your probably fine at 500ppm co2
You could go upto 30c with co2
You could use more light. It looks like your plants are getting Nitrogen toxicity because not enough light.

When you use co2 it only helps if all of your factors are dialed in. And then you add co2 you haveto add a bit more light, food, temps than normal.

My 2c. Anyone want to chime in i dont use co2 im just trying to remember.

Hey buddy, thanks for the reply. At the moment the plants aren't in the grow room, just in a temporary with normal atmosphere. So normal C02 of around 250/300.

Not enough light? They're babies and 3 foot away from a high power LED SK400+. I can move it lower and increase the PAR to 250/300 and see how they do? Just worried about burning them until such high intensity LED.

So it looks like nitrogen toxicity? Shall I flush them with a fresh solution?

Did you buffer your rock wool before you used it? Are you sure of your pH and the calibrations of both your meters? I have to agree with Projectinfo, your lights should be closer. While they are smaller plants, they aren't so small that light intensity is going to be an issue unless you just get the light crazy close; your PAR readings really aren't very high, even for a seedling. Your plants are green; if anything they may be having a little trouble with your N levels, but that is probably more a function of their current health. If you think it's an issue, just cut your nutrients back a little and see how they respond. Start with the fixed inputs; your medium and your feed / water. Looking at your picture, all your girls are exhibiting the same issues, despite a couple doing a better job of trying to grow through the problem. You also mentioned "definitely not over watering", are you sure you're not under watering?

Yes. Soaked rockwool over night in pH 5.5 water, then rinsed it through with the nutrient solution the next day thoroughly to flush out any left over salts/lime.

pH meters are spot-on, I'm using 3 x Bluelab systems (2 x pH dosers + 1 x guardian) in my mixing tank in my grow room where I mixed the solution up.

Do you think they will be OK for a couple of days until I can move them to the proper grow room? There I will be 100% sure of everything as I have a complete controlled environment with real time ph/ec/temp readings for the reservoir tank and also ph/ec monitor for the run-off, etc.

I'm not sure if I'm under watering as this is the first time doing rockwool. Basically I've been going each day and feeling the weight of the rockwool so see how saturated it and watering as necessary. I'm a bit concerned about over watering.

Tonight I will increase the PAR to 300.

I don't see a reason as to why they wouldn't be ok until you move them, but I don't think you're going to find your answer in doing so either. I don't use rock wool, so I can't comment on when and when not to water; that is better left for someone who has the experience behind them. It doesn't appear your room is too hot, it doesn't appear your lights are too bright and it doesn't appear that your nutrients are too strong. You seem confident in your meter's calibration so that doesn't appear to be an issue. Sounds like you buffered your rock wool correctly, so I doubt that's an issue. I would look at your watering, being seems to be a little bit of a question in your mind. I can only speak in terms of coco, but if you let that stuff dry out too much it will cause issues all day long. Perhaps rock wool has a similar idiosyncrasy? Ask the question in the Hydro section; you may get the answer you're looking for. Sorry I can't be much more help, but good luck.

One last thought. You mentioned a reservoir. Are you premixing your nutrients and storing them in a reservoir, even though you're watering by hand? If so, you may want to be sure your pH isn't drifting up as it sits there. Many experience this phenomena, and if it's happening and you're still going off the initial pH reading...well, there's potential for issues there. Otherwise, I'm out of suggestions friend. Never the less; good luck!

Hey buddy, thanks for the reply. In my grow room I have a huge 1000L reservoir I mix my solution up in. I mixed up the solution then put into large containers and took to the current room where they are to keep for hand watering.

The reservoir I mix it up in is monitored and pH adjusted automatically (see picture) - Ignore the readings at the moment because I've just put fresh water in to flush out the large big mama cubes...

Is it possible the ph could have drifted over a week or so in the container I was storing it in? I didn't think that was possible as the solution has just been sat in a huge container. I'll check the solution pH first thing tomorrow morning!

Nice set up! You are obviously way ahead of me in terms of technology. I like it.

As to the pH drift....absolutely it can drift way out of range over a week, depending on your nutrients, water, etc. I have read many times where the pH of someone's mix would drift out of range just over a couple of days. In my case, my nutrient solution will only drift maybe 3 tenths (5.8-6.1) over 4-6 days, but that's not a rule for anyone else, just my fortunate luck based on my inputs (Tap water and Jack's 3 2 1 Formula). The best thing to do is monitor it daily, without the automatic adjustments and see what it does. This might well be the issue for you.

Feeding too much. Look at the plant.

CannaCountry said:

Nice set up! You are obviously way ahead of me in terms of technology. I like it.

As to the pH drift....absolutely it can drift way out of range over a week, depending on your nutrients, water, etc. I have read many times where the pH of someone's mix would drift out of range just over a couple of days. In my case, my nutrient solution will only drift maybe 3 tenths (5.8-6.1) over 4-6 days, but that's not a rule for anyone else, just my fortunate luck based on my inputs (Tap water and Jack's 3 2 1 Formula). The best thing to do is monitor it daily, without the automatic adjustments and see what it does. This might well be the issue for you.

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Thanks man, will check the pH first thing.

hotrodharley said:

Feeding too much. Look at the plant.

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Can you elaborate a bit more? Feeding too much? I've only been watering it with nutes when the rockwool had lost 70% of it's weight, once every 4 days. 0.6EC isn't really a strong solution.

Justin Freidman said:

Can you elaborate a bit more? Feeding too much? I've only been watering it with nutes when the rockwool had lost 70% of it's weight, once every 4 days. 0.6EC isn't really a strong solution.

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You're somewhere between 300-400. That's starting for a plant in hydro. It's obviously a bit much for your situation looking at the plants instead of a meter.

hotrodharley said:

You're somewhere between 300-400. That's starting for a plant in hydro. It's obviously a bit much for your situation looking at the plants instead of a meter.

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OK. Cool. Thank you. I will flush the rockwool with RO 5.8pH water then give them lower strength nutes. Maybe 100ppm(500) calmag and 100ppm(500) nutes for a week or so.

Justin Freidman said:

OK. Cool. Thank you. I will flush the rockwool with RO 5.8pH water then give them lower strength nutes. Maybe 100ppm(500) calmag and 100ppm(500) nutes for a week or so.

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Give it a try.

hotrodharley said:

Give it a try.

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Thank you!

Hey Guys, thanks for all the help and feedback....

Mixed up some new solution this morning and noticed something funny. Normally when I mix my RO Water, Cal-Mag and Hesi-nutes the pH is ALWAYS around 6.0. This time on both Bluelab meters it was 6.3... I got out my calibration liquids and checked. SHIT. pH 7.0 was showing pH 7.4 on BOTH meters. That means my solution mixed at what I thought was 5.8 was actually 5.4. So looks like this is a pH issue and possibly overfeeding like hotrod said.

Mixed up some RO water with cal-mag at 150ppm (0.2ec) at 6.0pH and flushed the hell out of them. Will leave for 12 hours before starting to feed them again with 0.4ec (0.2ec calmag, 0.2ec hesi-nutes) tomorrow for a week before increasing strength.