Brown spots on leaf tips, is it calcium deficiency? & Questions about LST

Hey all, just wondering if anyone knows if this is calcium deficiency or something else because it looks like calcium deficiency but I give plenty of calmag & every additive bio diesel make so Im not sure it could be at this point. pH going in is definitely fine. Pretty sure she's 4 weeks into veg but hard to say coz I had a problematic seedling stage. Feeding at 900ppm in Coco under 200 watt led at 80%. Also doing low stress training for the first time & am wondering how to go about defoliation, should I take off all leaves covering bud sites in veg or wait until first week of flower to defoliate or just when she's getting too busy?I'm finding it difficult to know how to use the net as well, how do you water when the plant grows along the net? If anyone has any advice would be much appreciated. Thanks to everyone

900 ppm and you don't have tip burn. They do look very dark green. Very well done. How is your Ph? Could be a problem with calcium or magnesium.

Thankyou for your reply. Is 900 alot in week 4? The chart goes up to 1400 in week 6 of veg then the change to flower in week 7. The chart for week 4 is actually 850 ppm recommend but it's up to 900 with the extra calmag I'm putting in. That's what the chart says anyway. I got the full bio diesel nutrient kit with everything in it, they are a company where I am in Melbourne so I'm literally just following that. My pH going in is usually exactly on 6 but sometimes it varies to 5.9 to 6.1 but never under or over. Testing the runoff pH in Coco is literally impossible, learnt that the hard way lol. So what would you recommend? Do more calmag? If I do more the ppm will go up quite a bit because I'm already using more calmag to fix the problem that's why I'm confused it's only on a few of the bigger leaves so maybe it was an issue but isnt now.

Run nutrient through the pot then measure the ec of the run off.

I suspect by the colour you're feeding too much and you'll find the run off ec is too high.

You're in Australia it's hot, your environment plays a big role in the ec/ppm requirements, a hot dry room evaporates water quicker raising the ec.
(concentrated nutrient through water evaporation)

Star Dog said:

Run nutrient through the pot then measure the ec of the run off.

I suspect by the colour you're feeding too much and you'll find the run off ec is too high.

You're in Australia it's hot, your environment plays a big role in the ec/ppm requirements, a hot dry room evaporates water quicker raising the ec.
(concentrated nutrient through water evaporation)

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Thankyou for your reply. I was actually just thinking that the ec might be too high, I only just threw the runoff out so I'll have to test it tomorrow. Would you happen to know what ec it should be at? If it's over do I flush with crystal clear then start with lower ec? Yeah its been getting a bit hot here, I've got a small cooler for the tent I'll put it in there for during the day. My split system keeps the place pretty cool, the tent hasnt gotten hotter than 29 degrees yet but we aren't into the real hot summer yet. Thanks again

Don't use water to rinse the coco only use diluted nutrient (scientific reasons beyond me)

The ec/ppm is relative to your environment, I see your feeding 1.8ec (900 ppm)
If you run your mixed nutrient (900 ppm) through the pot and measure therun off.

If it comes out much above 900 ppm you need to rinse the coco so you're getting the same out of the bottom as you're putting in the top, you're re setting it so to speak.

Give it 2/3 days feeding your regular nutrient then test it again, if it's too high again you need to lower your input nutrient.

Example..
You're feeding 900ppm and you get 1200 ppm run off you need to lower your nutrient 300 ppm.

0.2/3ec above the input isn't a big concern it's to be expected over the day if it's hot.

Jfc, test the run off and rinse it back if it's too high.
I'd use 1.0ec to rinse the pot then finish with a regular strength feed.

Give it a few days then test the run off again and offset accordingly if it's much more than 0.3 or 4 over the day
(150/200ppm)

Star Dog said:

Jfc, test the run off and rinse it back if it's too high.
I'd use 1.0ec to rinse the pot then finish with a regular strength feed.

Give it a few days then test the run off again and offset accordingly if it's much more than 0.3 or 4 over the day
(150/200ppm)

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Ahh I see, so use the 900/1.8 through the pot then test the runoff, if it's over 0.3 higher then I need to rinse it with 1.0 then feed regular and test it again in a few days to see if it's over again. This bloody heat has really made it hard, the pests are crazy at the moment too.Thanks heaps for that, very much appreciated

BibbyMcBuds said:

Ahh I see, so use the 900/1.8 through the pot then test the runoff, if it's over 0.3 higher then I need to rinse it with 1.0 then feed regular and test it again in a few days to see if it's over again. This bloody heat has really made it hard, the pests are crazy at the moment too.Thanks heaps for that, very much appreciated

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Hey buddy, you only need to rinse it back if it's considerably higher than your input, for example if you use 1.8 and get 2.2/3 ec or more out

A rise of 0.3ec/150ppm ± over the day isn't unusual that's why we need run off, you are feeding to 10/15% run off aren't you?

Star Dog said:

Hey buddy, you only need to rinse it back if it's considerably higher than your input, for example if you use 1.8 and get 2.2/3 ec or more out

A rise of 0.3ec/150ppm ± over the day isn't unusual that's why we need run off, you are feeding to 10/15% run off aren't you?

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Hey there, yes feeding with at least 15% runoff. I fed 4 litres but didn't get any runoff because I missed a feed yesterday, oops. Stupid Christmas, everything gets too crazy. I'm going to make some nutes up now to feed her in the morning to see what it comes out as. Hopefully it's not too high. Haven't had any burnt tips as of yet so fingers crossed. Thanks heaps for your advice. Ive got a bloody whitefly problem now too so I've been battling that the past few days. So sick of these bugs. Hope you have a great time over Christmas & a happy new year

Ideally you want to treat run off like a religion, it's very important with coco growing in particular.

How did it go when you tested the run off ec?

I put 850 ppm in and 1000 came out, is that too high?

No that's not terribly high, tbh I expected it to be higher than that.

Is the nutrient your using coco specific?

Try feeding more often at a lower ec. Cut your strength to ¾ or ⅘ and water twice as often.

Big misunderstanding in the community when it comes down to feed frequency vs feed strength.

Star Dog said:

No that's not terribly high, tbh I expected it to be higher than that.

Is the nutrient your using coco specific?

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I though that too. Yeah it actually is for coco. It's called bio diesel. It's even got a Coco chart that I'm following, they make it here where I am. The bio diesel range doesn't seem to be too good for autos tho. So still no explanation for these brown weird spots on the tips, still getting them too only on the older leaves. The lower new growth is dying but it isn't getting much light. My auto seedling has a weird brown spot on it but I realised the light was waay too close so I've put the light up to 60cm, maybe that was the problem :/ I forgot about putting the light higher up. Explains the extra heat too. How are your plants going? I've got a few whiteflies too

ProPheT 216 said:

Try feeding more often at a lower ec. Cut your strength to ¾ or ⅘ and water twice as often.

Big misunderstanding in the community when it comes down to feed frequency vs feed strength.

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Hey that could be a good idea actually. I did test the runoff, I lowered to 850ppm and it came out as 1000. I also realised my light was way too close, oopsy