Hi,

I think I have LSF but i'm not sure. The plant in question has been yellowing since 12/12 started its now 22 days in. I first noticed the colour fading at the start of 12/12 and gave them 1ml grow 1ml bloom. This had no effect whatsoever so the next 3 feeds they got 2.5ml grow 2.5ml bloom. This has not helped either.

They had a spray of epsoms about a week into 12/12 and have been fed every 5-6 days.

The pics are not great but it looks like tiny rust speckles all over the upper fan leaves.

Click to view attachment

Click to view attachment

Important points

1. Its only on the upper fan leafs. Green healthy leaves are not affected

2. I have another clone growing beside it that is perfectly healthy. Only difference being it has been fed on ionic nutes and not bio bizz

3. temps are fine

What do you think? Can anyone see a Mg def in there?

Cheers

I'm going to treat for Mg def cos my plants have the same curling edges as djay's in his thread here http://www.uk420.com/boards/index.php?showtopic=121548

I've also improved air flow over the canopy as I suspect heat has something to do with it.

One question tho,

The plant is taking 6 litres before I get a run off so is 1 and a half tablespoons the right amount of epsoms I should add?

Just asking cos I've only ever sprayed them before

Cheers

I hadn't replied to this as I couldn't make it out from those pics, the rust spots you describe do sound like LSF but it's hard to say from a description.
I was going to ask how close the light is to the plants though. If it's only happening at the tops....

I dunno if I would treat with that much epsoms though. The dosage is a tablespoon per 5 litres if you are watering it in, but if you treat when the plants don't need it, it can lead to other nute lockouts.

Hiya mate i think your right in that its a Mg def, one big heaped tablespoon should be enough for six litres
Rj

The plant in question was about 7 inches away from a 250w, I think it could be something to do with heat cos the rusty plant is taller than the other one but not by much.

The link to the thread I posted mentions heat stress locking out Mg but I dunno. Theres still a fews days left till I water them so i'll see how they look then now that i've added another fan blasting at the tops.

e2a: If there no improvement next watering 1 tablespoon in 6 litres it is

Cheers

I'd be looking at heat issues and whether your ventilation is up to scratch before I'd go chucking Mg and god knows what in there

looks environmental to me.

sorry... missed the rust spots bit, this could well be lsf , but there is some fading between the veins which does look like mg def, what temps are you getting at lights off and how long is it before the pot becomes dry enough to water again ? if you are going to treat with epsoms i would half the risk and go half a tablespoon per six litres first then give it a week or two to see the response if things look to be improving you know your on the right track
Rj
e2a: as other members have said only do it if your sure nothing else is causing problems, temps etc , goodluck

So if it is LSF, what do you do? Is there a fungicide for it?

I have a couple of brown specks on mine, so i'm shitting myself now.

Good luck with yours BBB

E

Cheers wasabi.

I have some pics on my other thread called "Nitrogen Defficiency" about 5 below this one.

I'll check that LSF thread now.

Thanks

E