Rate of growth etc

[adeyren 14]

As this is my first ever grow would appreciate some feedback from you guys on the progress of my plants.

Am growing in a NFT system, 400w HPS light and Sensi parts A and B nutrients. Seeds were germinated on Jan 5th ie first put into a damp towel so progress is from that date onwards. Plants are 3 x Jack Herer and 2 x Super Silver Haze. Plant heights are 8 -9" or 200 -225mm now. My intention is to SCROG them soon. Am currently on a 18/6 light cycle.

When do you think is time to put them on a 12/12 cycle? and when would it be time to start SCROGing them? Also as you can see from pics have a few yellow spots (appeared last week). They seem to have stopped getting worse but they are only appearing on three of the plants? Any advice. Another problem i have is low R/H 20 -30% and cannot seem to get it up. Weather here has been extremely low last few weeks (average -1 to 4C) most days, would this have something to do with it? My nutrient level seems to be high ie 2260ppm using a Tri Meter. My water before adding nutrients is between 400 - 500ppm. Exactly what is the conversion to EC using a Tri Meter?

[adeyren 14]

Yes got an airstone in there. Only a small one though. Bigger one??

[adeyren 14]

Thanks Tokage. Sad?? in what way my friend? To me as a novice they seem pretty healthy, apart from the yellow spots LOL! They sure smell good in there!!!

[adeyren 14]

Wow Tokage, from the size of your airstones i definitely need BIGGER airstones. Mine is probably 5% of the surface area of yours. My airpump is a double feed one so will get bigger stones tomorrow. Thank you friend. Any thoughts on growth rate?

[Dust 6,284]

Hey man when you say 1° it's not in your growroom i hope ^^

Tok might have a nice idea with the bigger airstone, they won't complain to more air anyway so no risk in trying

I ain't a hydro grower so i will let them answer

good luck

[adeyren 14]

Sorry for the confusion on the temps. They referred to outside temps. My rez temp is a constant 22c - 25c but room temp sometimes gets a bit warm ie averaging 33c.

[Dust 6,284]

ok good good, think 25° is a little too hot for water try to keep it more on the 22° side

As long as the extreme temperatures are not during the whole day it should not be a big problem, of course if you can find a way to fix it with your cold ir outside they would only benefit from it