Can someone please help with this deficiency

[Deforced]

Hi guys, I've got a deficiency in my flood and drain iws system. I will try to explain everything.
I started hand watering at first vegging for around 8weeks and everything was fine, I moved into the system for another 4week and things were going great at first then started to see spots on my leaves ( i will attach photos).
I checked my EC and it was wast 1.4 so I flushed them loads from the top.
I am now at 1.0ec and ph is 5 8-6.2
Medium is coco/pebbles 60/40 mix
Humidity 50%
4x600w hps light, I've made sure they are far enough away from the plants.
Room is 2.4x2.4x3m
Feeding canna A+B base nutrients, I dropped out the additives to make things simple until I get ontop of the deficiency.
Ec of my tap water is 0.5EC which canna says there is no need to add calmag.
I have sprayed calmag onto the leaves in 1week intervals and not seen no improvement at all.
Any help would be great as they are getting really bad now, I can't seem to find what is going wrong and it's getting worse by the day. Thanks

 

[steamroller]

Best I can do without pics .

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[Aqua Man]

Link your water report?

feed volume, frequency and delivery method?

Pot size

not near enough information to be sure but I’d say likely you are not feeding in a high enough volume often enough.

you likely need to be about 4-12 times a day depending on pot size and flushing from the top often.

read these then see what info and questions you come up with

 

[Aqua Man]

Marijuana Watering, how media, pot size/shape and environment affect it

Ok lots of posts on how to water plants. So I thought I would put together a thread on how different factors contribute to different results that ppl see. This will be a long read based on my personal knowledge, opinions, research and others work to consolidate information for our members. I'm...

www.thcfarmer.com

 

[Deforced]

I will attach a video as I can show all the plants in the room

 

[Aqua Man]

HOW TO WATER COCO FOR BEST RESULTS.

Ok writing this cause i see this issue often and rather have a thread to link than explain this each time. This is not my work but a collection of info from many members here and I have put into practice myself. So first off COCO is NOT soil. For best results we want to keep it saturated...

www.thcfarmer.com

 

[Deforced]

This is the video, thanks for your replies.

 

[Aqua Man]

This is the video, thanks for your replies.

Watched 10 sec. Definitely a nutrient lockout from buildup. Common to see in the stages after stretch to harvest from to little runoff and or not having enough irrigation events. In your case the latter

 

[Aqua Man]

What I suspect is to much dry back. As evaporation and uptake occur the nutrients become more concentrated and since water flows from low salinity to higher salinity across root cells the plant stops up taking adequate nutrients and you see multiple nutrient deficiency and signs of water stress. Add to that once coco reach about 30% saturated the roots can no longer pull the water from the media.

so imo start flooding every hr at a min even 30 min. That media is so aerated you will have a very hard time to over water even if you tried

 

[Deforced]

OK thankyou for your reply, I will up my irrigation and also would you keep ec at 1.0? Or up that too? Thanks

 

[Aqua Man]

OK thankyou for your reply, I will up my irrigation and also would you keep ec at 1.0? Or up that too? Thanks

1.0 to 1.4 but it’s important to keep them hydrated because it will jump over 2 in a short period in smaller pots if left to dry out

 

[Deforced]

1.0 to 1.4 but it’s important to keep them hydrated because it will jump over 2 in a short period in smaller pots if left to dry out

OK, sorry a forgot to mention they are in 10.5litre pots I'll sttach a photo of stems to show size of plants

 

[Aqua Man]

And make sure to too flush 1x pot volume of half strength nutrient solution from the tops every few days to a week to clear buildup above the flood line

 

[Deforced]

 

[Aqua Man]

OK, sorry a forgot to mention they are in 10.5litre pots I'll sttach a photo of stems to show size of plants

Yeah so 3 gal per plant once a week too fed with 50% nutrient solution

 

[Deforced]

And make sure to too flush 1x pot volume of half strength nutrient solution from the tops every few days to a week to clear buildup above the flood line

You sound very familiar with this system? Everyone who I have asked on here seem not to know about the iws flood and drain?

 

[Aqua Man]

View attachment 1234621

Good job cleaning up those bottoms. If they are dense remove the older largest fans leaves. They are the least efficient for photosynthesis contrary to what most think

 

[Aqua Man]

You sound very familiar with this system? Everyone who I have asked on here seem not to know about the iws flood and drain?

Auto feed coco in 1 gal pots lol. Was feeding 14 times a days.

never done flood and drain but same concept with some twists. Done pretty much all but aeroponics. But fully understand it.

 

[Deforced]

Good job cleaning up those bottoms. If they are dense remove the older largest fans leaves. They are the least efficient for photosynthesis contrary to what most think

Thankyou, I will do just that. Would you know roughly until I see an improvement if the flood frequency is the case?

 

[Aqua Man]

Thankyou, I will do just that. Would you know roughly until I see an improvement if the flood frequency is the case?

You won’t see any other than in new growth. The damaged leaves will get worse and fall off. Not a big deal at all. New growth should look better within days of the rest of the parameters are in line