[Doubie]

Hi guys, can anyone help me diagnose this?

Hydro DWC
Hard water Growers Ark nutrients 1.3 EC
PH 5.8
Water temp 18/19c
Great white shark bennies
Meltrop Calgreen and canna rhizotonic via foliar once a week

I first had it down as megnesium deficiency but she's not responded to 3 days of Epsom salt foliar sprays and the leaves are still browning.

Large older leaves get those rust spots, and new growth looks pale green in the middle but darker near the tips
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Cheers guys and girls

[duke]

hi i take it you have looked at the roots and are sure all is ok down below?if the roots are good i would have said underfeeding but at that ec that shouldnt be the case except with the odd gross feeding strains but you would know that better than me ,does your ec include the background ec of your water?

[2scoops]

Looks a bit like calcium deficiency to me, rust spots and crispy curly leaves. Here take a butchers http://www.growweede...ciency-cannabis

[Doubie]

Cheers lads, I'll check the roots and give her another few doses of Calgreen

I'm starting to think it might be a phosphorus deficiency from pics on Google

[mellowed]

Checked ph pen calibration mate?

[Dekay]

Its not magnesium def the colouring doesnt really fit, first thing I would do is always calibrate pens like mister mellowed says, it could be phosphorous, or calcium but why whats not right, whats run off readings.

[mellowed]

Its dwc deeks. Its locked out or ph is out. My background ec is 0.2 and only have a prob with cal/mag when the ph is either to low or to high depending on what the plant wants.........unless there is root issues.
I never use mag/cal additives either.

Drop the ph if the probe is fine.
5.6 should be great.
If the ph is dropping then leave it a few days to go where it wants.

Dont know why i didnt post all that beforehand.

Ow a back ground ec would help

Im bored and stoned and getting smoke in my eye as i type.

[duke]

hi did he say what the background of his water is? i reckon its hard water and not being accounted for in his final ec ie my water is 0.50 ec so adding nutes i would make my reading 1.7 ec giving actual feed ec value of 1.2 otherwise you permanently underfeeding imo as much of that bg ec is no good for plants as food other than a bit of calcium.peace

[mellowed]

Come on doubie.
We all bored and wanna work this out for ya lol

He did say hard water so i assume its 0.5 plus.

[2scoops]

Adding too much calcium can interfere with uptake of phosphorous and you`ve got hard water which has lots of calcium in it to start all be it shitty calcium carbonate that`s hard to use by the plant , but still some gets in and does get used, what im getting at is the medium will still have plenty in whether or not the plant can use it and it may cause lockout of P. Just summink to bear in mind when adding calcium, tis why i like foliar feeding to correct and bollox.