Hi.
I have a mg deff which I think may have been caused by ph rising.
What is my best course of action to recovery? I read on another forum guide that one of the worst thing you can do is treat with epsoms if it was ph related.
My background is .3 ec,feed(in total) is 1.15 in a hope to flush(48 hrs now) but the usual getting worse/fading/getting a brown shade.
Plants are around 8/9th internode, in large rockwool blocks under 600w mh, 26" away.

MG is normally locked out by ph too low. If the pH is too high, marijuana suffers from a lack of iron, zinc, manganese, copper and boron. If the pH is too low, it lacks phosphoric acid, calcium, and magnesium.

Click to view attachmentClick to view attachmentThanks...I have the ph absorbsion/rejection charts.
The horse bolted days ago...but thanks for the intrest.

I think it happened through not giving enough time to settle the ph after the res fill. I had to add some ph down...then up, to get the 5.6 I was aiming for(usually rising to 5.9 over the course of a few days--a good range)
I dont normally use ph up,just for emergencies.

There must have been a conflicting ph level in the blocks which I think changed the overall ph,when the feed was administered...just a theory.

Please help stop this for me,it happens far too often,and given that epsoms ALWAYS fry them more,I have to consider the advice in a the sticky on another forum that epsoms are a no-no if the mg lockout is caused by ph problems.

So what course of action SHOULD I take instead?

I need sound advise quickly,weak feed seemingly isnt helping.

Its not a good thing to ph up and down your res. Either up or down but not together. If I understand you correctly your ec is .85 which is a tad weak for a plant at 8-9 internode. I would have my ec at around 1.2. Prepare your water by airating it for 12 hours, add nutrients and adjust ph then apply. Preparing your water this way will help to stabilise your ph

1 teaspoon/ltr sprayed at lights out, see how they go after 3-4 days, if no improvement spray once more



Well your ph wasnt that far off anyway and i think the above is rubbish

Owd

They were sprayed with epsoms yesterday...and the pics are todays. There was no hint of brown edges before they were sprayed. And I had already dropped the ec to 1.2,from 1.35,in case the cause was due to nute burn.

Are the brown edges a later symptom of mg deff...or over ferting? i.e. should I up the feed AND epsom every 3 days,or will the sudden strength change Cause further lockouts?

Everything was perfect when they were on formulex.

I know to use only ph up,or down. I had to get some up, after a miss ph reading friom the ro water I was adding(have come to the conclusion that there was nothing in the water to bite against,so when i'd ph'ed it down from 6.5 to5.6,I was adding far too much ph down,and as a result,when I added to the main tank,It must have gone waaay down)
Please, is it still deffinatly not ph related? and I DO epsom again?

So long as ph dont go outside 5.2-6.5 then theres really no need to worry, especially if it was only a day or so

If you sprayed yesterday give at least 3-4 days for the plant to absorb and use it

Dont spray more than twice though

Your ec seems fine at 1.2, that shouldnt overfert them as its not a strong mix

Owd

Also its not a good idea to use just ro water imo, mix it 75% ro and 25% tap

Owd

Thanks Owd...so is the browning of the edges mg related? The feed is around .9 at the mo 1.2 total. Do I up it to 1.5 total then,despite the run through0(recurculating coming out at 1.2 total still?
I'm confused,as I am always bieng told to keep it around the same as going in. If I up it now,wont this fry them?

Nearly everytime when youve overferted either the very tip of the leaf burns first, or if its an excess of Nitrogen the leaves go really dark and curl under like a rams horn

If you use only ro water you need nutes specifically for ro water as most foods contain no or very little calcium, they rely on the calcium already in tap water

This is especially so with one part foods

Owd

Thanks Owd
I never use just RO water...Ijust didn't mention it as I thought it was safe to assume we don't.
So for the record 30/70 tap/ro topped with formulex to .35-.40 then add normal nutes(sensi 2-part in this case.
A pic in the plant abuse chart commonly linked on this forum shows the start of nute burn on the serations,and comment that if it never gets any worse,theyre prob just fine.
I am aware it starts on the tips first,but can't find mid-burn pics,only early,or severe.

Are you advising me to up my feed to a total 1.5ec (0.3 background)? I will try more tap water in the mix also...40/60
At the mo its the browning edges i,m worried about,and the fact the run off is just 0.02 higher than going in...does this not mean theyre happy with 0.8ish?

Your opinion is highly respected Owd...please clarify

Please Owd

No mate 1.2 total, and ph at 5.8

I would forget using the formulex and just use your sensi nutes, no need to use both together, and dont worry yourself about runoff, i never have, run off is usually higher so thats normal

Owd

Ahh , I had been wondering about this . I.e about Nitrogen levels . Iv'e got this on a few sets of leaves on one of my plants. Didn't have a measuring cup for a couple of weeks and was guessing the ferts . (bio bizz). Turns out i was adding 2ml Ltr grow... day 17 of flower now. on ot1's regime properly now

Nice one , Owd

Remember i'm running a recurculating tank,so run off will matter a lot if the ec is to stay steady. With these probs I have,the ec is constantly rising(which is why I had added RO water to top-up/weaken with.My theory being that if I add tap water,i'm adding 0.5 of crap,into an already weakish mix of 1.2) Am i right in assuming that JUST pure water evaporates?
0.9 feed with plants this size seems low,but your the Boss
Why did they do magnificent on Formulex up to ec 1.2 for 3 weeks with no worries? (I'd tried these early stages with Pure RO,so they'd been getting the full 1.2 up until switching to RO+tap with sensi grow)?

sorry to hijack

is it better to spray woth epsoms than to water with it??

When in veg or start of flower, yes.

Friend of mine recently installed an RO filter thinking it would help his hydro grows.
He spent 2 grows chasing his arse with loads of minor nutrient deficiencies......he tried allsorts of ratios of RO and tap water to no avail.
We read on another forum about people making up a background EC with formulex before adding their main nutes, so he tried this and hasn't looked back since.

I think anyone who is using a fair proportion of RO water will get the benefit of a more stable pH and EC, but a lot of problems with micro nutrient deficiencies.
That's been our experience anyway.

ETA - that is of course unless you are using something like GH 3 part nutes where you have much more control of the micronutrients.

Yes, definately.

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Ok...so 24 hrs later and a lot worse. Only had 1 dose of epsoms 36hrs ago.
As Owd has pointed out...nute burn starts at the tips,but this defo started at the edges(although yellow tips have been present.
I've read in the past that nute burn affects the whole plant-is this correct,and if so can I rule it out?
IS it nute burn? or fungal,or a symptom of mg deff?

(N) burn & (Mg) deficient.

As Ot says in his post here - http://www.uk420.com/boards/index.php?s=&a...t&p=1421533 - you have to find out why (Mg) is being locked out. Too much (N) may lock out (Mg) etc...

Thanks Bish
I'm confused as to the nute burn.This has come on is the last 36hrs,and they had been on 1.2(0.85+0.35) for about 4-5 days.I really do feel that this is caused by the epsoms(1 tsp/litre) I know your guide is good and worthy,however I know for a fact the ph had dropped for a couple of days,and cannagraphic guide clearly states NOT to epsom if the mg deff is ph derived.
This wrecks EVERY grow...4th one in a row now(hope i can stop it this time)
What course of action is best now,and is could this info apply to mine?

And ahem...by misting do you mean gentle misting over the top...or drenching top+underside with a mister.?
Could it be that I OVER epsom them EVERY time?

I reckon Owd's covered it all mate. It looks like a touch of (N) burn to me, but then i don't grow Hydro.

A fine misting to cover all leaf surface is fine.

Hope they pick up

In my experience excess nitrogen causes lush dark green growth followed by rams horn type twisting of the leaves which is clearly not happening to your plants. It looks very much like they aren't getting enough N and an ec of .85 is rather weak. I would say that they are hungry. The leaves are slowly turning pale but the veins are still green, thats what happens when a plant starves, it starts to eat its leaves. If it was my plant I would slowly up the ec untill it showed signs of recovering. Leaves that yellow rarely go back to green but you will notice that fresh growth will be nice and green.

What do the roots look like? Are they healthy looking white or tan colour?

what about on ot1s schedule he says week 3 of flowering give a feed of epsoms

i assume he means watering with it

Click to view attachmentWell this was the other day.
I followed advice of ec 1.2 (.035 background) and they had had 1 dousing of epsoms the day before this pic.

Click to view attachmentAnd this is todays.
I'm not convinced that this is the road to recovery.
The pics depict the plants being a lot greener than they actually are...which is quite pale.
Any further help?

What brand of nutes are you using stripey?

Click to view attachmentIv'e started a new thread as the last one is getting long.
Here's a pic from a couple of days ago.
I followed advise from Owd+Bish, and gave one misting of epsoms,and continued on ec of 1.2 (0.35 background)

Click to view attachmentAnd this is her today.
Very much worse than the other day.
Any ideas?

I started them on formulex and 100% ro water...magnificent growth for 2 weeks up to 1.2!!
Then I put them in main grow area,and changed to tap+ro water made up to 0.35 with formulex, used with sensi grow 2-part up to1.3
Curently tap water and sensi grow at 1.2 (0.35 background)
Roots nice and white cos i'm using oxy plus(cos i'm in large rockwool blocks nft style,but they don't ever seem to dry out so it's more preventative than anything.
I'm also using silicon+ at half strength
ph around 6 at mo
Showed signs of numptyness as soon as they went in the tent.
Temps 26-29deg
2x600w halide 28" away
2x 6" extraction on full
1x5" in and lots of passive in.
Mister bringing rh up to 70%

could be underfed looks a bit like potassium deficiency

Yeah well I was diagnosed with that on my last grow...and the 1 before.
All start the same,and end the same...crispy leaves.
Last grow told to feed 1.4 and see.....excelerated doom
The one before told to drop to 0.8 ...same result.
Loads of advice freely given,but none that has worked for me so far. I'm sooooo pissed off.

are you using the same nutes on your last growes ?

Try them on formulex again.......usual EC though, not just to make up the background.
If they start to come round then I would say the sensi nutes are not quite right for your water.

past 3 were in coco so no(1st one was an absolute monster)
The next 2 wrecked.
Which is why I switched back to sensi 2-part which i've had success with in the past,along with the fact I bought an ro unit(which is what I once read advanced base their figures on.)
Iv'e tried measuring run off,but always higher than going in.
Nutes are brand new.
Pens calibrated
90l res. recurculating

what i would do is flush your cubes clean just ph 5.8 water
then make a fresh tank up with a ec of 1.8 to 20 and see what they like in a week

So what has fried the leaf edges?
ec never been past 1.3

NPK are mobile nutrients so if you not supplying enough they will take it out there older leafs to supply new growth could be possible cause or maybe you locked it out with to much Epsom or maybe to much acids there could be a few reasons for it
also you run a nft system they can handle higher ec levels than grown in a medium because with mediums they will build up nutes to whats in your tank i think it potassium problem you have got


lack of nutes can make your plants burn up commonly mistaken for nute burn

Most helpful yet.
How do I react to my own system then?
I'm in large rockwool blocks,in nft 1cm gap (roots already touching spreader(and some trying to shoot out of the side of the blocks)
If I flush the rockwool,do I then not touch again, and leave to dry,just using the nft trickle to feed? knowing the shoots from the sides will wither before reaching the mat
Regret putting em in big blocks but there ya go.

if most of the roots are in your blocks it could be a ph issue causing lock out
get a syringe and suck a sample out you block and test it ph and ec
your blocks should be sitting on the spreader mat for them to keep moist
once you have flushed your blocks make a fresh tank up and i would run the pump 24/7
plants of that size should have good roots into the mat by now next time just use little blocks

Ok so I messed up by sitting the blocks on a grid 1cm above the spreader mat then!!
I thought that the roots in the blocks would suffocate if kept constantly wet?

So how does the air/feed flow through the blocks and not stagnate?
Shure i've read about tile spacers,golf tees and pizza lid thingies all used to raise the blocks

the oxygen will be supplied with water running over your roots once they establish
and as long as the cubes are just on a damp mat not a water logged mat they will be fine even if the cube is totally soaked it will still hold about 20 percent air they dont want to sit in puddles but once your roots establish this will be less of a problem you should check ph and ec in your blocks and if ya can place the blocks on the mat

No chance of moving em. Roots are well into the mat(quite pleased with that part)
Did the syringe thing,all fine in the blocks,but then it would be cos i'm chucking 2l,twice a day over 'em just to make shure.(also why i'm using oxy+ so they don't drown.
Is there a chance they'll be ok suspended 1cm if I flush 'em every couple of days to keep 'em wet?

once the roots establish they should be ok but keep the blocks wet until so