New Grower Yellow, pale green dropping leaves, 3rd week 1st auto grow - advice please

[Bexter]

Hi there,

It's almost 3 weeks since my 3 Northern Lights autos sprouted and I'm not sure whether I've got an over-watering problem and / or ph problem? Am growing in biobizz soil with perlite, 135w led, in small grow tent. Was using tap water but switched to distilled water (ph 7) ove rthe weekend. The leaves started to going pale green with greying / yellowing just over a week ago so I gave them 1/4 dose biobizz grow and fishmix which am also using as foliar spray. I use the spay 2/3 times per day. Not sure if I should stop that now are they appear to be flowering for the last few days. The leaves on 2 of the plants are quite pale green (one plant is ok) but all 3 have yellowing older leaves. They are also dropping - I have been watering every other day. Am waiting for my ph pen to come thro the post. Anyone able to help?

 

[beenjammin]

hows it going im no proffesional but i recently had the same problem around the same time with my plant and it had alot to do without having a ph pen or the right nutrients.. i wasnt giving her any nitrogen and the bottom leaves started gpoing pale and then yellow just like you said i lost three sets of leaves from not giving any nitrogen and from not having her in airy soil. I started with the nitrogen and put her in a better soil mix that this guy called muddy from here told me and i saved it from dying completly the fifth and sixth set are nice and green and its strarting to smell a bit so ima get a tiny yield burt better then no yield lol the only thing i can say is good luck and i hope that ph pen comes fast

 

[stoneyhomer]

pics would help but douse sound like nitrogen deff or lockout due to ph ph pen is the one must have tool (imo)

 

[AndyBotwin]

I agree with beenjammin that you want to get a handle on the pH ASAP. Once you start giving nutes, that tends to drop the pH levels quite a bit if you're not adjusting for it. Get too low and you can lock out nutrients and release toxins to the roots. Another thing to think about at the 3 week mark is CalMag or at least some epsom salts. Autos seems to be very hungry for magnesium and if the don't get it from the soil they'll take it from the fan leaves.

 

[Bexter]

Thanks a lot everyone. Gotta cheap PH pen - have recently spent on decent led lighting and a good carbon filter / fan kit, so had to keep cost down (will get a better one next month). First of all - yes, I had over-watered, so have been letting them dry out and at least the leaves are now pointing at the light. I took the PH - yep, you're all right - too high at 7.8. Never seen bottom leaves that brown!

So this is what I think I should do - but please feel free to comment if I'm wrong. I'm gonna water them either tomorrow or Saturday morning, whenever they've completely dried out. I'll use distilled water (tap water in London is very alkaline) - ph7 - then add the bio grow, fishmix and then start with 1/4 dose of bio bloom, cos they're definitely flowering, and build up from there. Once I've done that, I'll let it settle for about 20mins. Then I'll measure the PH of the water and adjust. Got some lemons - have read the juice is good for lowering PH and are safe to use.

I guess this is a big learning experience for me, being my first proper grow, so I'll be pleased with any yield. Need the weed for medical use. Good luck to all of you with all your grows. All I can say is if I get these plants thru, I owe a some people on this forum a massive toke or 3 lol!

:smokebuds:

 

[AndyBotwin]

No worries Bexter, we'll help you get through to harvest. I'm not familiar with the Bio nutes, but others I've used will drop the pH quite a bit. So if you're starting with water at 7, it's quite possible the nutes will drop the pH into the ~5 range. Your plan to add them to the water and let them sit for a while before testing is a good one. Have you tested the runoff from your soil yet? If not, when you add the water capture the first drips out the bottom and test them for pH. It's not an exact science but it will give you a idea where you stand.

 

[Bexter]

Cheers Andy. Got some baking soda just in case the PH drops too low - got lemons to so I've got both sides covered! Not test soil runoff, but will do tomorrow when I water. Pretty sure I'm gonna lose bottom fan leaves on all of them. Bought some CalMag too, which will come on Monday. They're just over 3 weeks old.

:smoke:

 

[JM]

you can also use white vinegar... 1tsp per gallon wil drop ph about 1.0


heres a chart:




those will help you understand WHY whats happeneing is happening... :smokebuds:


also reccomend you read the 2 guides in my signature...

cheers!

 

[Bexter]

Thanks a lot JM. Really useful charts. Leaves still standing up, so got to grips with not over-watering. Watered yesterday morning. Added Bio Bloom for first time, 1/4 dose. Got some Topmax too, so will add that too, as well as CalMg when I get it though post. Also added some Bio Heaven for plant stress and is supposed to boost nutrient take-up bigtime. Got the PH to 6.7, so was happy with that. Plants def looking happier, one of them has kinda exploded into growth! Am hoping other 2 do the same. Think I've lost those bottom fan leaves tho. Hope that doesn't affect yield too much.

Andy, you were right. I stated with the distilled water, PH 7. When I added the nutes, I let it settle for 30mins. PH was then 5.5.