Okay, I had a couple of people in the local stores tell me I wanted to keep the nutrient solution oxygenated and I should have one in there. If you didn't have one I won't worry about it. You had said you put your screen about 15 inches above the growing media, I have seen many different numbers on how high to put that, Do you always put it at that height or is it more dependent on the plant? Also, how often do you change your reservoir solution and between changes do you just add water or a weakened solution or full strength solution? Last question, do you leave your fans running 24/7 or just when the lights are on? I will putting together my thread later today, I will post the link as soon as it is up.
Thanks very much,
Jack
I've heard similar things about oxygenating the nute solution, but so far the lack of an air stone doesn't seem to have affected my results too much (as far as I can see...). I sort of figured, perhaps naively, that the plants would tell me if they were lacking something throughout the duration of the grow cycle.
The height of the screen is really difficult to pitch. I struggle with it almost every grow. Is it too high, is it too low? What kind of phenotype is this particular strain? Will it get really stretchy during flower? It's almost impossible to predict in someone else's grow environment, so my best advice is to keep your first plant small. Small plants are much easier to manage, and the only reason to grow a large plant off the bat is greed. Most first time growers expect ounces upon ounces of bud returned for their months of 1st growing efforts, when really the most important lesson you can take from a 1st grow is simply keeping the plant healthy. Yield comes with experience, in my opinion. You really learn a lot from watching a plant grow and bloom.
I read somewhere when I was deciding on attempting a ScrOG on screen heights that for Indicas, the screen should be 12 inches above the growing media, and for Sativas, the screen should be about 18 inches above. I don't think it's that cut and dry, and each grow space needs to be analysed individually for the best position of the plants, screen, and bulbs in the space. With that in mind, for your first attempt, I wouldn't have the screen any higher than 12 inches, in fact, possibly a few inches lower. You'll want to veg (and maybe top) your plant until it's a couple to a few inches below the screen. When you change to the flowering light cycle, the plant will stretch into the screen and roughly triple in size from when it was in veg.
If you place your screen too high, it won't be fit for purpose as the plant will be far too big to comfortably fit inside your box, which will reduce your final yield. Place the screen too low, and you might not produce a plant with as many bud sites as you would've liked. My point: it's a balancing act that you'll want to tinker with over your first few grows until you find what works best for your space.
I use a 20L reservoir, which I pH balance every few days, and which I dump and refill with fresh water and nutes every 7-10 days. I rarely add water and supplemental nutes to an existing tank, I usually just dump and refill every week (give or take a few days). The bigger the plant gets, the quicker she absorbs water and nutes, so if you're using a smaller tank, you might need refill more frequently when your plant is flowering.
I keep my fans running 24/7 - I don't want any stale air trapped in the box when the lights aren't on. If I had two intake and two exhaust like you, I would consider having all four on when the lights are on, and maybe switching one intake and one exhaust off when the lights go out. I guess it depends on the ambient temperature in your box when the lights are off. If your box is in a cold room, the fans might draw in too much cold air when the lights are off, so I suggest you do a test before planting to monitor the temperatures in your box with lights on, lights off, fans on, fans off, etc, and make sure what ever combination you use, your temperatures remain within recommended thresholds when the lights are both on and off.
Looking forward to your grow, dude. I'll try to offer as much help as I can, but I'm really just a hobby grower, so I can't predict how much help I'll be. My knowledge of what to do when things go wrong is limited, but I've made plenty of mistakes and miscalculations along the way.
Loving it!!! Got some pics of your current grow?
Thanks!! Sure, here are a couple of pics just taken of my Ketama (Moroccan Indica landrace). She's a few weeks from seed. Short, bushy, with super-tight internodal growth. Just the way I like them, because this pheno lends itself well to a ScrOG - the canopy usually stays fairly uniform without much training.
