Nitrogen Def?

[WisdomKarp]

Hey all, I'm wondering if it's a N deficiency I've got. They're not autoflowers, they're a photoperiod bubblicious. Into flowering, and a micro-grow inside a pc box. There was a period of temperature fluxuations before, due to random mid-april below-freezing cold snap, but that was a while back.


As you can see, it's been trained and stuff, just so I could get the most out of my limited space, and apart from a nagging feeling that the temperature might be dipping at night, it seems to have been going fine, bar the discolouration of old leaves. I was just wanting expert opinions before I add some ammonium nitrate to the next watering, rather than my usual 5-5-10 fert. It's under a red CFL 12/12.
Thanks!

EDIT: I'm fairly sure it's not a pH problem, since I do always make sure my water (tap water left out for 24 hours, then left on top of the grow box to warm up to the temperature of the grow so as not to shock the plant) is pH-ed to 6.6ish. +/- 0.1 at the most.

 

[Muddy]

Welcome to AFN. That's looking more like the beginning of a P deficiency. But before doing anything I'd suggest you check the pH of your run off. Even though you are pHing your feeds if your soil pH is off it could be causing a lock out situation.

 

[CGR]

Welcome my friend you have come to the right place ...........looks like muddy got you covered, he's help me out alot along with others here ....:smokebuds:hit this.....did you stop over and introduce your self? if not do so it helps to get help....

 

[WisdomKarp]

Hey, thanks for the replies. Firstly, I'm not actually a new member, I was here a bit before, but then I didn't come on a for a while and I think my account got deleted due to inactivity ^^; But thanks for the warmth in general though ^^.
Also, apologies if I didn't put in that much detail in the first post, I was a bit high at the time of posting >.>.

And ahh, alright. I've never been sure whether to trust run-off pHs, but I'll make note of it. Should I water again tonight or should I wait until it's next scheduled watering? (which would be either tomorrow or the day after, depending on how dry the soil gets).
Also what would quickly sort a P deficiency, if it is that? I'm in the UK, if that helps, brand-wise?

 

[Muddy]

I would wait till your next watering. Atami makes a product called PK13.14 which is 0-13-14 NPK. Other manufacturers make similar products. But I wouldn't be surprised if it's your pH.

 

[GoAuto6]

Rough Calculation Guide:

Here's some good info on ph.....
If your runoff pH is higher than your starting pH, use this equation to determine your soil pH:*
Soil pH = Runoff pH + Difference

If your runoff pH is lower than your starting pH, us this equation:
Soil pH = Runoff pH - Difference.

For example, say your the starting pH of your solution before it goes in is 6.5 and the pH of your runoff is 7.0. The difference is +0.5, so using the above equation:
Soil pH = 7.0 + 0.5*
Soil pH = 7.5

If your starting pH is 6.5 and your runoff is 6.0, your difference is -0.5 and using the above equation:
Soil pH = 6.0 - 0.5
Soil pH = 5.5

​

 

[WisdomKarp]

Thanks for all the replies =). I'll water it tomorrow with ph-ed water. Also, if it is a pH problem, what's the quickest/most efficient way of fixing it? I remembered that the base soil is peat based, so that might be nudging it towards the acidic side. I'm not sure how long dolomite lime takes to take effect, but I have some if needed. I dunno, I realise it's just conjecture at the moment until I do this. I'd water it now if it weren't for the fact it's almost lights out time and I generally water during the morning.

 

[WisdomKarp]

Okay, I watered, and yous were right, it's the pH in = 6.6, runoff pH = 6.1 =/.
How does one go about fixing this?
UPDATE: Doing a quick google search tells me that pH can actually vary somewhat according to the time?? (http://www.greenmanspage.com/guides/phfacts.html ) First I've heard of this, but then again, I am fairly new at this >.<. (If it is relevant, I watered about half an hour after lights on) Also, according to the above formula GoAuto6 mentioned, this means my soil is at 5.7 ...

 

[WisdomKarp]

Oh-oh..

Alright, I'm basically going to give it a couple days from the watering before flushing it with water at 6.8-7.0, that seems to be what various google-searches etc. have shown up, but I'd like a confirmation on that if possible, since I'm painfully aware that I'm still really new at this >.<.

In other news however, I'm starting to worry that the plant might be hermie-ing, since there's things that might be balls, but I'm not sure, I've attatched the best pictures I could get with my phone camera. (Don't have any better =( ).


Also, whilst I was there, I took some of the delicious looking frosting starting to appear ^_^. That and a couple of photos of the plant in general.