A couple of questions. Pics included.

[MaoZebong]

Hey guys. I'm growing an NL#9 plant, and have a few questions about it.
It's been vegging for a little over 2 months I'd guess, and its stem is still only around 30 - 40 cm tall. I have LST'd it, so I suppose that's the reason. But still, it's very slow to stretch. I've raised the lights to around 20-30 cm above the plant, and it's still quite slow. Bushing out nicely though. Another mistake I think I've made is not making a good enough dirt mix. I think it's too dense, but the stem looks really thick and healthy.

Anyway, how long, from the first sings on the plant, does it usually take for nutrient buildup in the dirt to become a problem? There are a few tiny spots, like nutrient burn, or "nibbles" as if an insect had eaten it, but I've seen those since the first two leaves, and it's not gotten any worse since. Am I doing something wrong, or is it more or less natural? There are examples in the photos, I just hope they're clear enough for everyone to see.

Another thing is that it's really hot and arid in my grow area (30+ centigrade and not even registering on the hygrometer), but the plant still seems to have an okay time. I suppose this can also contribute to the stunted growth? I'm only using a 125w CFL veg bulb, and I've tried to keep it a bit cooler by "manual AC", and it works amazingly well, lowering temps by around 10 centigrade and increasing humidity by 30%+, but only for a very very short time, so it's really frustrating to keep up. I've ordered an electric picnic cooler, though, and plan to make an electric AC out of it, which will hopefully also contribute some humidity. How badly will my plant have reacted to the high heat/low humi over such a long time?

EDIT: And I almost forgot the most important thing I wanted to ask. Trimming and pruning. I trimmed it quite a lot just a week and a half ago, so you could easily see the stem through the foliage, and now it's completely over-grown again already, to the point where new fan-leaves are again shading for other nodes. Should I keep it well pruned, or let it grow to a bush?

Anyway, here's the promised pic.
(And it goes without saying that this is my first ever grow of any kind.)

 

[billmoe93]

I kind of think you are compounding your problems.

You shouldn't move the light away from the plant to make it grow taller. Its growth is stunted probably because of all the adverse conditions its facing. Taking away light by moving the lamp higher and trying to make it stretch itself when its already stressed will lead to thin weak stems. Your plant will most likely stretch and fill out a lot in the first weeks of flowering.

Humidity, is important. When its too low the plant releases water and keep doing so, until it dries out. If it gets too dry then the stomata will close and stop taking in C02 and really hinder growth. You need to be vigilant with the water, but from the pics other than being small it looks pretty healthy.

You know your temps are too high, so you know you will need to cool that down. That will also help with the humidity.

Nute build up depends on how much you are feeding them. If you feel like you might have overdone it flushing and starting over with fresh nutes isn't a bad idea. From the pic they dont look burned though.

Trimming/Pruning is a highly debated subject, just do a search and you find plenty of info. However I don't think its a good idea to be cutting any leaves off your already stressed plant when they are vegging. It needs the leaves to collect light, what part of the plant is collecting the light is not important right now. Some might say its never important, but thats another debate altogether.

Anyhow I feel like I ranted long enough, dont get discouraged because it looks healthy. I think if you fix its environment and maybe stop cutting leaves off you can cure the stunted growth. gl

 

[MaoZebong]

Hey Bill,

Thanks a lot for the comprehensive answer. I'll lower the lights again, and then when I get the cooler, I suppose more of the problems will be eliminated. I've already watered twice with a diluted nutrient solution, around a fourth of what I've usually used, and I'll go back up in steps. I'll start flowering in the first couple of weeks though, as I'll become homeless in around 2 months. Time is running out unfortunately.