Leaves turning light green...again

[BAMWW]

Problem: Leaves turning light green on two different strains.
Medium: Plagron lightmix with added guano and worm castings
Feed: 1/4 strength Plagron Alga Bloom and 1/2 strength green sensation. They have only gotten two feeds so far
Strain: Heisenberg special and Walter White. The pics are of the Heisenberg at day 44
Climate: 26C with lights on, about 17 or 18C with lights off. Humidity 55%
Additional info: I've had this problem on all my grows so far. I always get N toxicity with dark green leaves and leaf tips curling at about week 4. This is then followed by leaves turning light green when they are putting out some decent buds. I didn't use any veg nutes this time except for Power roots and enzymes which are additives from Plagron and still got N toxicity. I usually keep an eye on my PH but haven't been checking run off on this grow. It has always been good anyway and I still adjust the PH of my water and feed. It's worst on the oldest Heisenberg but only because it's a few days ahead. The other plants are showing it now too. Any ideas? I know I have hard water so maybe this is a factor and there are also some brown spots on a few leaves.

 

[LED Borg]

Hi mate, goin in the deep end with a shot in the dark here,
maybe the too hard water has locked out them out?
Cant feed on the soil feed but devouring themselves instead?
Treatment, give them some Epson salts, maybe also give them that in bottle spring water, ph at source 6.2 stuff, even sparkling, they love the co2.
Only saying that cos ive had the same thing and it worked for me. They didn't turn back green tho, but she stopped eating them so fast and produced more green growth.

 

[BAMWW]

Hi mate, goin in the deep end with a shot in the dark here,
maybe the too hard water has locked out them out?
Cant feed on the soil feed but devouring themselves instead?
Treatment, give them some Epson salts, maybe also give them that in bottle spring water, ph at source 6.2 stuff, even sparkling, they love the co2.
Only saying that cos ive had the same thing and it worked for me. They didn't turn back green tho, but she stopped eating them so fast and produced more green growth.

I'm beginning to think that might be the problem as well. I had ruled out the water being a factor because I had problems on my first grow while using rainwater. Of course it was my first grow and I was using chemical nutes so I was probably doing 10 other things wrong at the same time!

I know the water is hard because i tested it with an ec meter which i have since broken. I think it was like 400ppm but can't be sure now. I remember reading here that was high anyway

 

[LED Borg]

yeah man, no harm in giving em a bit of the old salts anyway, then its the waiting game eh?
they should still bud up ok tho, still got plenty of green growth underneath.
Are you also using LEDs? could be a CalMag def coming on, plant magic's CalMag+ is excellent for sorting that out.

 

[Piotrek506]

Hi guys,I am with Borg on that one.
It looks like typical cal mag deficiency , it is pretty common in flower as they need this two elements in higher quantities than in veg.
The leaves won't repair them selfs (the rusty spots) but the new growth should be healthy . Get youself a bottle of cal mag (it is essential) and you should supply it with every watering.
Because of the stage of deficiency I would foliar feed for faster recovery.
Get alga mic it is bio bizz product it relives stress and helps with the absorbtion rate of nutrients that has been supplied, mix it with Epsom salts (Mg source) and you should get nice green colour back in no time ...
It is sooo common you should expect it with every grow you run , that's why you should start adding it in between week 4 and 5.
One more thing try to keep the temp gap between lights off and on to minimum, otherwise it will cost you at harvest time a big time.
Good luck mate

 

[BAMWW]

I'll try some cal mag and see what happens. I forgot to mention earlier that I added a spoon of Epsom salts to one of my waterings last week. How much should I be using?

Light is a 600w HPS by the way not LED

 

[Piotrek506]

I use 1/4 of Epsom per litre of water , once a every two weeks starting week 4.
You need to keep an eye on the issue, end don't use it if you don't have to . And if plant needs more give it more often but don't over do it, it will affect the plant.
The best way to administer it is foliar feeding.

 

[LED Borg]

yeah bro, tip of a teaspoon dude straight into a 2L bottle of nice pure spring water is the way I do it. wait a bit tho, as the salts take a bit of time to dissolve in the water, best thing still, get the water to room temp first before adding the salts, not straight from the tap if too cold. The salts will just collect at the bottom. Even fine salt can do that if the water is too cold.
I also agree about foliar feeding aslong as the leaves arnt that close to the bulb itself, or scorched leaves is what youll get along with rust spots.
Don't worry tho dude, ive had plants really really badly affected with CalMags, all the way to the end, still got a good yield and still got good tasty buds,. blue cheese auto is was, you'll find some strains are more tolerant to CalMag def than others, in fact it can work the other way round, too much Calcium or Magnesium will lock them out just the same.
One other method is too give nutes one feed and plain water the next, I just prefer to do what the plant is telling me, the colour of the leaves etc... some times I lay off feeding tho and they seem to love it, all strain related tho, as some like feeding constantly, some don't
Give em the salty feed, give em 3-4 days and you should see the buds start swelling again bro.

 

[BAMWW]

Will try this tonight but I can't say I'm convinced it will work. I had tried using the epsom salts on previous grow with the same problems and as I said i added some to the feed of this grow last week.

I think I have some kind of additive with all the trace elements including mag so I'll dig that out and try it too. Hopefully something works!!

 

[Piotrek506]

Just use Epsom salts with every watering for couple of weeks and they should get green again, rusty spots will not disappear but if you use cal mag along side with Epsom the new growth should not be affected and that how you know if it the def cleared .
A 1L of water use : 1,5 ml cal mag + 1/4 tea spoon Epsom, get if you can Rizotonic (it also acts as stres reliveand ) 2ml/1L
Don't let soil dry completely (causes deficiency due to lack of any means to transport up and down the plant essential minerals, plants need moisture).
Good luck brother,