How long for 18/6?

Discussion in 'Lighting' started by b0naf1d3, May 6, 2011.

  1. If a plant is 4 weeks & only 5 inches tall, how many more weeks should it be left under a 250 watt blue spec. Light with 18/6 ? basically at how many weeks should the hours of light and dark be changed?? And what should the hours be changed to?

    @ how many weeks?
    How many hours of light and dark?

    Your replies are greatly appreciated.
  2. You mean when to switch the hours for flowering? It depends on what sizes you want them to go into & finish flowering at. At 5" they could be flowered now or they could be topped now and flowered in a week or two. Most plants need at least twelve hours of uninterrupted darkness each day to flower, so the times are changed to 12/12 when flowering starts.
  3. #3 b0naf1d3, May 6, 2011
    Last edited by a moderator: Mar 15, 2016
    Well what would you suggest ? Would the plant become effected if I left it at 18/6 until it would reach ten weeks?
  4. Generally you leave a plant in its vegetive stage (18/6) until it preflowers. Preflowers are the first few white hairs emerging from the stalk where some branches meet the stalk to show that its a female and has reached maturity. Most plants will pre-flower in 6-8 weeks from seed.

    You can flower whenever you like by switching them to 12/12 lighting. Otherwise they will stay in a vegetative stage. Switching to flower before pre-flowering will diminish yield - but can be done.

    You can also leave the plant in veg for as long as you like. It will continue to grow and create more potential buds sites = more overall yield. Just don't forget to transplant/feed when they get big!
  5. #5 Jellyman, May 6, 2011
    Last edited by a moderator: May 6, 2011

    The only effect on the plant from vegging longer is that it gets bigger. As long as you have the room & light intensity to grow larger plants, doing so should create more bud to harvest, as well as increase the time until then. While some plants grow more or less in flowering, you should expect plants to about triple the size you start flowering at.

    Personally, I top and leave two nodes on the plant. I then top the two shoots that grow from the top node, leaving one node on each. By the time these two nodes get their four shoots growing, the two shoots from the lowest node on the plant reach canopy level. The plants go into flowering with six stalks that are all at the same height and will all form similarly sized colas.

    If you have separate vegging & flowering areas, you could start new plants now and once the clones are rooted/seeds are geminated, flower your current plants & start a more complex training program with the new ones. That way you can get finished buds asap and have trained plants ready to flower when your first ones finish.
  6. Thanks jellyman & moto823
    Lights will be left on 18/6 until it hits 8 weeks, then moved to 12/12. @ jellyman: I don't mean to sound like a dunce but I don't understand that whole " topping nodes and topping shoots" lol but I'll do more research and consider it. Here's a recent pic of my first girl ( OG herojuana kush ) I hope everything goes well with her she looks pretty bad to me compared to when I first got her 3 weeks ago.

    Attached Files:

  7. When the plant grows it has a main stalk/stem and leaves. The bulge in the stalk where two leaves, one on either side, grow from is called a node. At each node there is a small growing shoot on both sides, where each leaf meets the stalk. These shoots are just like the top of the plant where new leaves form except they don't grow as quickly. If you cut off the top of the plant, these little shoots will start growing faster. This is called "topping." Any growing shoot/stalk/stem can be topped, causing the smaller shoots at nodes under where you cut to grow faster.

    Left alone, most types of pot plants will form one large, main cola (bud). Topping and some other techniques cause two or more colas to form and increase yield.
  8. Looking @ the uploaded photos above, when would you think would be the best time to start the "topping" on this specific female? Now ? About a week or two ? Maybe three?
  9. She's plenty big enough now. Those little bunches of leaf at each node will grow into new stalks when topped. It'll help to feed her after topping. A ratio close to 5-4-3 should work well.

    The way she's folding upwards and the discoloration looks like she isn't getting watered enough and/or is drying out for other reasons. If so, that should be corrected before any major cutting.
  10. She is receiving very little nutrients to reduce chance of her becoming burnt. ( 1/2 teaspoon of monster grow & 4 table spoons of grow big all mixed in a 5 gallon water jug). There is insufficient funds for HP+ & HP- so she's getting distilled ( drinking) water only( mixed with the nutrients). She gets fed every time soil is a little less than moist. ( about every 72 hrs ).
  11. Nutrient burning has become unusually less common over the years. More often people end up causing deficiencies in attempts to prevent burn. I can assure you that your plant can handle full doses (or even stronger ones) of those ferts you're using. Just alternate with plain water whenever giving the plants full fertilizations.

    Try to find a source of extra Phosphorus to include in upcoming feedings. I strongly believe you'll get a good response from it.
  12. Where can I buy this phosphorous? Lows? Home depot?
  13. Apply phosphorus at how many weeks?
  14. Can a 250w bulb bee used all the way till harvesting? That's what she's currently receiving.
  15. Most garden centers are the best local places to buy soils & most fertilizers. Search Google for the closest & best rated garden stores in your area. Some of the best sources of Phosphorus are Bone Meal and most Bat & Seabird Guanos.

    Phosphorus is one of the two most important nutrients for plants in any stage of growth. Seedlings start needing weak nutrients when the 3-bladed leaves start growing in and P is one of them. They'll then need a great deal of it throughout their lives. If you know how much fertilizer your plants can handle, you give them all they can take without burning at each fertilization, and alternate with plain water every other watering. If you give the plants about half what they can handle or less at each fertilization, then you can safely fertilize every time. Some growers like myself still reccomend getting plain waterings in regularly.

    Yes, a 250 can be used in veg and in flowering. It can only strongly support about 22" of vertical growth and less than two feet squared in floor space, though.
  16. I dont know if shes ok though.& she's growing really slow. Do you think she is being watered correctly? She is being watered about 5 cups of water every 72 hrs. Is it ok if she's being watered while she is receiving light?
  17. How am I suppose to know how much phosphorus is enough for one pot/plant?
  18. Imho the best way to really find out how much fertilizer your plants can handle is to start with a good typical NPK ratio for your growth stage and increase the doseage until you see burning. Your plant should do well using a nutrient mixture of around 6-5-3 while in veg. Watch the tips of the lowest & oldest leaves on the plant for signs of burning when turning up the ferts.

    You can use lemon juice or vinegar to make small adjustments in the water pH. PH drops showing a range from 4-8 can be had for as little as $7 at some Garden or Hydro stores and can last a fairly long time. I highly reccomend getting some. They'll help tremendously.

    Watering Frequency: The ideal moisture level for most soils is when a handful drips just a few drops when moderately squeezed. Soil mixes with near-ideal drainage characteristics will only hold the right amount of water, letting any excess drain out the bottom. Spraying the surface before watering, using room-temp or slightly warmer water and watering slowly will all help minimize the liquid that is wasted running out the bottom.

    You can tell when to water by the weight of the pot or by waiting until the top inch or two of soil (for that sized pot) is totally dry. You can stick a finger in to feel how dry the soil is. Watch the lower leaves of the plants because underwatering will cause them to dry up and die, ending up all tan and crispy. Overwatering usually causes the leaves and then the whole plant to droop.

    Your plant looks like it may not be getting enough water for some reason. There's a chance the necrosis is just from P def but the way the leaves are reaching straight upwards looks like they need more water. Try to soak the soil well when you do water and start pH'n your liquids. If it helps, one drop of lemon juice (tested with the dropper I use, of course) adjusts three cups of water .2 acidic.
  19. What is your opinion about miracle grow soil? That's what she's planted in right now.
  20. From the point of view of someone who uses very good organic fertilizers, MG fertilizer is crap and so is any dirt that comes with MG already in it. I don't want to make anyone who uses it feel bad- it can be used to grow healthy plants. There are just a number of better solutions out there imho.

    So far the best way I know of to find local garden centers is to go to Google and type in, "Garden Center" "Nursery" and "Hydroponics" separately, each with your zip code next to it in the search window (e.g. nursery 90210). Click on the little map and find the stores closest to you. Call and/or visit them to see what they have. I get the big bags of good organic soil locally for $8 each, from a wonderful Garden Center that employs great people; all stoners.

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