Leaves paling after heat stress?

[AutoManCan]

Hello all,

I have moved my light etc to resolve the heat issue and stop furthing heat stress BUT, the leaves are now going pale and I am not 100% sure on the reason.

At first I thought nutes, but the soil is BioBizz Light Mix and the plants are only 12 days old, surely it can't be nutes?

Anyway please take a look and let me know what you think.

[joker_the_smoker]

see people having alot of troubles with the bio bizz stuff.

looks like its got either heat stres or wind burn going on with the way leaves look and also the colour might be light bleaching as you running a 600w on it up close?

see what other chaps say ...

[Clunge Muncher]

Id say heat stress and bleaching from having the light too close.

[AutoManCan]

Id say heat stress and bleaching from having the light too close.

If it is light bleaching I will take that not as detrimental as nutrient deficiency

I have raised the light to 20" now so I will see how we go.

Part of me can't help but feel the 250w HPS at 10" would be better than 600w at 20". What do you guys think?

[Smokedragon]

Part of me can't help but feel the 250w HPS at 10" would be better than 600w at 20". What do you guys think?

I run a 150w HPS and I still keep it about 18" from canopy top. my probe thermometer puts me in the low 80's most of the time (80-84). I'm careful to move the light up when the canopy is heating up even if I think it would slow growth. Nothing slows growth like a damaged and stressed plant. Better to cool the canopy and slow down a few kph vs burning your buds and screeching to a halt by force of heat.

[AutoManCan]

I run a 150w HPS and I still keep it about 18" from canopy top. my probe thermometer puts me in the low 80's most of the time (80-84). I'm careful to move the light up when the canopy is heating up even if I think it would slow growth. Nothing slows growth like a damaged and stressed plant. Better to cool the canopy and slow down a few kph vs burning your buds and screeching to a halt by force of heat.

Yes I see what you are saying.
At 10" with the 250w HPS though I have temps at the canopy of around 26°C which should be fine. No signs of heat stress or bleaching too.
I will stick with the lighting at 20" for now and see how it goes.

[kbag]

Less watts less heat 10x better than more watts and to much heat especially when plants are young.

[Smokedragon]

26°C

I successfully remembered not to say miles per hour and instead kph and then I went on to forget to convert Fahrenheit to Celsius. 26C ~ 78.8F... looks good man. If you have an excess of light and temp controlled, now you are ready to elevate CO2 for increased production..

[Greengrass]

This might sound real dumb to the experienced guys here but bear with me

But to me your soil looks low in the pots ,is there any chance heat is gathering around your plants that your fan blowing across the tops that it can't
Dispel it causing a heat well?