Need advise (beginner)

[hustle]

Greetings,

I cant express how much I learned from the tutorials and forum on this website I thank you from all my heart.

I am a beginner and currently my setup is 2’x2’x3′ grow closet with spider farmer LED sp1000 (100w). I need advise regarding the LED light I am currently in seedling stage growing 3 plants and dimming on the LED is 50%. the guidelines from spider farmer is to increase the dimming to 75% in vegetative stage however I am not able to sustain temperature. currently with 50% dimming i am able to maintain temperate between 26.5 to 27.5 Celsius and humidity between 45% and 50%.

When increasing the light power to 75% temperature increases significantly to 29 - 30 Celsius and humidity drops below 40%. spider farmer is also suggesting to increase dimming to 100% in flowering stage and as I read temperatures in flowering should be between 18 - 26 Celsius.

My question is can I complete my whole grow cycle at 50% LED power? is this something achievable that can result in good flower? taking into consideration i am facing significant temperature problems when increasing LED power.

Also to note i am growing in soil (peat moss + perlite) in 1 gallon fabric pots. The distance between the LED and the plants (seedling 14 days old from placing seed in soil) is 63 cm or 24.8 inches.

Appreciate any advise, thank you!

[golfnrl]

Hello hustle Just curious, is that the light that spider farmer recommends for that size grow closet? Yes you can complete your grow even if you must dim your light. The distance from canopy is critical to keep from burning your plants. In that small space the power will need to be turned down to cover your heat concerns. The lights spectrum is most important. The intensity of the light only helps it penetrate the canopy. Do you use a PAR meter? I use a Photo Bio Phantom. Photone is free and gets good reviews. You need to be able to measure the PPFD of your lamp. I use this guideline, I think I copied it from GWE. Get your PPFD within that range and you will be OK.

Seedling/Clone 100-300 PPFD
Vegetative 250-600 PPFD
Flower 500-1050

[golfnrl]

You are spot on. The light's intensity is primary driver of yield but it isn't the sole factor. The light is the plant's energy source. Even the best and most powerful light cannot overcome a poor overall environment, and vice versa. It's a balance of factors that produce the best yields.

You want to run your lamp at the most powerful level that you can for your setup without harming your plants. I would say that if the lamp is dimmed the total power draw is reduced. A reduction in power won't have a noticeable affect on the light spectrum. Can there be too much light? Yes. After a certain point when the plants cannot utilize the amount of light they get and/or the lamp is too close to the canopy you get burnt tips, tacoing, bleaching, etc.

I use HLG lamps. Last December I harvested 42oz from two plants under a 600 W LED dimmed to 70%. The dimmer on my light has ten clicks. I start at the 2nd click when the plants are seedlings and increase as they grow maintaining the recommended distance from canopy. The PAR meter helps to determine how much light the plants are getting. Using a combination of dimming/increasing power and raising and lowering the lamp gets me within the PAR chart I use. And If I think they need more they get it. If I think they need less I do that as well. Watch your plants when you make changes. They will let you know if they like it or not. You'll master it soon enough.

[Smallgrow]

Dimming your light will reduce its power consumption
if your at 50% it will not use 100w

[hustle]

thank you so much for your inputs! it means this will definitely affect my overall yield

[Chipmunk]

Are you using an exhaust fan ?

[Smallgrow]

That is a very small tent you have hustle If you don’t have an exhaust fan it will be very difficult to manage heat. Some people will open their tent door part or all the way when the lights are on too reduct heat.

[hustle]

oh yes i do but not something big or what is usually used as i observed in grow tents, these things cost 4x if i want to get them to where i live.

i am actually using a small AC infinity fan as exhaust its 12v computer fan than delivers airflow 104 CFM which i also got at an expensive price $45 for a fan, im in the middle east so yeah buying things from the US have import and custom charges im managing the grow with the resources i can get.

as per your experience Chipmunk and Smallgrow is this enough for this size of grow space? or should i add another one? appreciate the advise!

[Chipmunk]

If the 104 cubic feet/min is accurate then I would say ok. Your tent is less cubic feet than that. Dangle a piece of tissue paper in front of the fresh air opening. If your exhaust system is working ok the tissue paper will be drawn to the opening and opening the tent door like smallgrow mentioned works well and you're putting more co2 in your tent that way for sure. Good luck

[Chipmunk]

Also do you get any negative pressure when the tent is closed up except where fresh air comes in? The tent walls should draw inward some in my opinion