brown spots on a couple of leafs

[longtimefirsttime]

Hi guys its my 1st grow so looking for a bit of advice if possible.

Iv got 2 autos in coco, that are in week 6-7 from seed. one was starting to show a little nute burn on leaf tips (so i thought) so i dropped feed a little. But now I'm seeing a couple brown spots on just a couple of leafs. and development seems to have slowed a bit. have been healthy up to now.

From what iv read it looks like Magnesium def? but would like opinions pls.

auto, in coco. 10l pots.

600w hps duel spec. 24/0

Temps - 25-26

R/H 45-55%

Background ec - 0.01

Current feed is: add calmat to get water up to 0.4 - then light dose of canna boost - then add canna A and canna B - final ec is 0.8 ( i was feeding 1.0 but dropped it back a little in last few days.

I water everyday to 20-30% runoff

PH 5.9-6.0

I started 2 seeds a few days apart, same seeds, the other one is looking perfect. they have been fed same feed all along.

Any ideas lads and laddettes?


Cheers

[longtimefirsttime]

tap, tap, tap. Is this thing on?

[Old Skool Dude]

Doesn't really look like a Mag deficiency. Have you looked on the underside of the leaf with a magnifying glass to see if you have any little enemies living there?

[Herbitual]

You mean your EC is 0.1 or genuinely 0.01?

I've not grown in coco so feel free to ignore, but I can't help feel that being 0.79 or 0.7 over base is too high? (Or indeed, 0.99 or 0.9 over base)

Anyhoo - bumped if only to get a coco'er on here.

[longtimefirsttime]

hello mate,

0.01 its not a typo. Thats why I use calmag to get to 0.4 ec then add normal amount of nutrients.

You mean your EC is 0.1 or genuinely 0.01?

I've not grown in coco so feel free to ignore, but I can't help feel that being 0.79 or 0.7 over base is too high? (Or indeed, 0.99 or 0.9 over base)

Anyhoo - bumped if only to get a coco'er on here.

[longtimefirsttime]

Doesn't really look like a Mag deficiency. Have you looked on the underside of the leaf with a magnifying glass to see if you have any little enemies living there?

No critters. its deffo some kind of nutes/ph issue.

[M_C]

I'd give her a quick Epsom salt spray... a lot of autos can be very demanding in mag. That said, your coco should be buffered - or is it a generic coco block?

[longtimefirsttime]

Im using canna pro coco. has been fine until a week or so ago.

I gave it a but of a flush with weak nute solution (ph5.9)then started normal feed again. Growth has picked up but leafs are defo bit more yellow than the healthy one, and its just not quite as healthy. But still cracking on with flower. I was feeding at ph 6.0 - 6.1 when the issue started, so iv dropped bk to 5.8 for now.

The other plant that is same, on same feed and looking sweet.

I'd give her a quick Epsom salt spray... a lot of autos can be very demanding in mag. That said, your coco should be buffered - or is it a generic coco block?

[M_C]

Ya can't beat a good phenotype