First Grow - yellow patches on leaves - overnight

New to this so any input welcome.

Yellow patches appeared on fan leaves on 2 of 3 plants - overnight. Concerned because it was so sudden. A couple of leaf pairs on each - differing heights

Plants: 3 x Lemon Haze photo clones

Status: 2 weeks in veg

Height: 10" tall each.

Growth Rate: 1" per day

Medium: Canna-soil Pro in 5 gallon pots

Nutes: Canna-vega 1:200 (every third water)

Water: pH 6.5 (thirsty girls, drink about 1.25 litre each a day with minimal run off

Tent: 4x4x7

Lights: 18/6 600W HPS (I know MH is preferred - I was informed that timing was more critical). I can swap back to fluro if needed. Lights were at 20" from canopy - increased to 26"

Fans: Circulate, In/ out, carbon scrubber, negative pressure.


Day: 30 deg C/ 32% RH

Night: 20 deg C/ water spill in tent last night had humidity @ 94% before caught and vented.

All have been growing well and consistently - it is the speed of occurrence on 2 of 3 plants that has me worried!

I have not found a way of bettering my day temps (bat wing reflector, not cooled).

Hoping I haven’t missed something. I will add a couple more images soon.

Do you know your runoff tds/ppm? Daytime temps are really high as well which will be causing a big uptake in nutrient rich water, that can in turn lead to burn as the plant struggles to process the extra nutrients it’s getting. Have a look at inkbird type controllers. I have mine set to bring exhaust fans on if it gets too hot in there. Be careful if you do buy a controller as some control humidity and some control heating/cooling

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Thanks for the input! No, I don’t have a awy of measuring runoff - I am in soil - I thought that was a aquaponics measure?
I was wondering about the nutes. Is it best do give them some pH balanced water? Or let them adjust?
I’m not running a controller at the moment - just learning where my balance is (only second day under real lights).
Under fluro in the same tent I was holding 23C & 60+RH - it is the heatload from the light (non vented) that has bumped me +10 C & -20% humidity. Tempted to go back to the fluro lights - they were happy…
was trying to do the right thing by giving them lights. Possibly too early in their life?

I’m also in soil and monitor my PPM and PH constantly. Water till you get a slight runoff in the saucer and check that. I use Apera and Bluelab. Big lights gave me heat stress as well. I checked my HPS and they were up around 600°C if I remember. I always give my babies plenty light as well and just watch for burn


Ok cool.That is something else I’ve learned. Will have to get my hands on the meters. For now - it sounds like fresh water and run off to dilute the existing. I’ve lifted the light higher than suggested to try and improve things. Is the something that is easily recovered from? Thinking I might put the HPS away until they grow up a bit…
Just about to upload some pics

Hps is an awesome light. Metal halide for veg though and cfl for seedlings. MH has more blue, hps is more red for flower and seedlings seem to respond better to cfl.

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I just use water and let them adjust. Works for me. My grow just now.


My girls (L to R = 1, 2, 3)

Large images, single file.

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Looking good, touch of what looks like nute burn on some of your leaves but looking good :heart_eyes:

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1.1, 1.2

2.1, 2.2

3.1, 3.2

That is a relief! I will give them a good drink of the fresh stuff. I will just have to keep a close watch on them.

Thanks for the input @Davyg :partying_face:

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Anytime, source a tds/ppm type device and you will get eyes on what’s happening down below :sunglasses:
Take care

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On my shopping list! Great tent btw! That is quite a forest! Do you not scrog? Your cola heights are all over the place! Still manageable?

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There’s a scrog net in there somewhere :scream::see_no_evil::rofl::rofl:. My colas are stretching for the sky and nature has taken over. In my defense they are all at different stages. There’s clones, sativas, indicas and autos in there. Some have just started flowering, some are mid way and some are closer to harvest. I even have two that are just showing preflowers :scream:

The inside of your head must be an interesting place!!!

Were you a juggler in a past life? My three stress me more than I them! And they are identical Sativa triplets!

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Wife says my head is going constantly. I don’t get peace but it keeps the voices busy :see_no_evil:

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If you don’t have a ppm/ph meter how do you know your ph. I had those color leaves on seedlings on the bottom but I believe it was because I tried some distilled water and didn’t ph it. I use bluelab meters


Thanks. I might be fortunate that my tap water, when filtered gives a tested pH of 6.4 - 6.5 consistently. I leave it sit for 24hrs so that the chlorine smell dissipates. I haven’t had to tweak it since I started checking it about a month ago.
That is a gadget I’ve had my eye on though.

Thanks agan @CottonUpdate