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First grow, a lot of questions concerning light, heat and food


New Member
Strain - Indica Super Skunk
# of Plants - 8
Grow Type - Soil
Soil Type - "Atami - Janeco light Mix": ATAMI Janeco Light-Mix Soil 20L
Soil - pH 6, 12-14-24, 1,2kg pro 1m³
Grow Stage - Veg
Medium - Organic soil + perlite
Light - currently 2x55 Watt Mammoth neon
Nutrients - What's in the soil + Root Booster + Sulfus Gold ABC
Water PH - 6 -8 (explained later)
RH - 40% to 80%
Room Temperature - 20C - 32C (explained later)
Room Square meters - 1,2m x 1,2m x 2m
Pests - None

Hey guys,

I want to apologize in advance for the long text, but I really want to get to the ground of my problem. Therefore I`d like to tell you, as detailed as possible, about my grow. I have to say, that this is my first real indoor grow.

I started with germinating 10 seeds about 1 month ago. 8 plants grew roots. I put them in Jiffys under a dome and when the roots started to outgrow the Jiffy, I transplanted them to bigger pots.
Since then I made several mistakes that definitively influenced my plants negatively. Now, after a month and a few days, at least 3 plants do not look very well, as you can see in the pictures.


pH mistake
Due to the fact that I believed the water pH in my area is about 7, the lack of a ph tester and the characteristics of my soil (ph 6) led me to believe that I don't need ph control. I was wrong.

I purchased a cheap ph tester and found out the ph level of my water to be 8. That might have been a problem. In the beginning my seeds did not germinate as fast and the did not grow as fast. After I regulated the water with common , I could really see the improvements in the plants. So, I believe that the high ph has definitely been a factor inhibiting growth.

Container mistake
As I've already mentioned I transplanted the seeds to Jiffiys and then to bigger pots. Those pots were too big. I over watered them the first time a gave water, because the pots were too big and did not evaporate the water fast enough. So, I had to wait more than a week to water for a second time. Next grow I will user much smaller pots.

Heat and light mistake
My setup contained in the beginning a 400 and 600W lamp, 400 for growth, 600 for flower. But, because I did not want to use the 400W on those small seedlings I bought a 24w Energy saving bulb with the light spectrum "cool daylight". It worked for a couple of days, but then I had the feeling that the plants did not grow any more, even after I put the lamp really close to the plants.

I therefore decided to employ the 400W. But, because it was pretty hot here a month ago and I did not anticipate the heat development of a 400W all my plants got heat burn in their 2-3 week after germination.
I placed the lamp somewhat higher to maintain the temperature at about 27°C. The plants burnt at about 32°C.

But as it turned out, the 400W was too far away from my seedlings, or something else was wrong, because they stopped growing (or grew very slow). So, after I was fed up by the constant monitoring of the heat and the stunned growth, I bought a 2x55W grow light, that could be placed directly above the plants because of the low heat development.
And it worked! The plants started the grow again straight after I changed the lights.

I have to mention here, that my ph tester and the lamps came with the same shipment. Therefore my ph water level AND the new lights could be the reason for the improvement.

Nutrition mistake Most important part!!
At the same time that I switched to the 400W I thought it was a good idea to give my plants some nutrition. I got the ABC mix from Sulfos. Because I was not sure about that I tried it with the 2 biggest plants I had at this moment. I really watered down the nutrient solution to about 1/2 of the recommended amount. But, after two days both plants got nutrient burn. The bigger one could obviously cope better with it, but the smaller one was looking really bad for a few days and is still a weakling (see pics).

Is this really possible? How can 1/2 of the recommended dosage be too much for plants 2 weeks after germ? Is says clearly on the bottle that you use it straight from the beginning. The guy at the grow shop where I purchased it was "100% sure" that this cannot happen.

Was it maybe due to the fertilizer in the soil? Was it just too much? Interestingly, I have not given my plants any nutrition since and I'm really unsettled about that fertilizer topic. I don't want to burn them again.

So, what do think about that? Could any other of the mistakes be responsible for the poor development and symptoms of nutrient burn?

And would you change the lights to the 400W for 1-2 weeks before going into flowering? The heat is not an issue any more because it got colder.

Please recommend when I should fertilize them again, especially because some have entered the vegetative state already.

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New Member
The more watts used, the better the yield and the better the roots can grow. I'd say definitely go back to the 400W is temps aren't a problem. Beware though, the 600W will give off more heat so be prepared to deal with that if it comes to it. A small clip fan blowing on the light might cool it down a degree or two (Fahrenheit) while providing more air circulation. If you can put more reflective material on the inside of your tent I recommend that also, just to cover up anything non-reflective. If your medium is organic then the natural biological processes taking place in it should buffer the ph from what I know. It is also most likely providing extra nutrients to the plant, but I wouldn't know how much. I think tweaking the feedings would be beneficial until you find the sweet spot where the plant can uptake the nutes without burn.
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