growing in rockwool

Discussion in 'Hydroponics / Aeroponics' started by mobby420, Nov 16, 2007.

  1.  
    mobby420

    mobby420 Well-Known Member

    im going to try and make it quick and to the point, im new here and this is my first grow. i germinated my seeds in rapid rooters, and then placed those into my hydro set up which consists of a tray with 8 3 inch rockwool blocks, under that i have a resevoir with a pump to water all the plants(the tray drains back into the resevoir)..... its been about 2 weeks since they were seeds and the roots are starting to come out the bottom of the rockwool blocks.... do i need to put rockwool slabs under the blocks for the roots to grow into ? also my plants are a little bit droopy and the leaves are all going in different directions? could that be over watering or over nutrients? People have told me to water 20 min every 2 hour,s i have found that is way too much and the pump only goes on now 4 times a day for 30 min each time! any siggestions or info is greatly appreciated ,thanks!!
  2.  
    Muffy D

    Muffy D Well-Known Member

    You only need to water rockwool once a day....but it depends on your setup. Take an extra rockwool cube, soak it, set it next to your setup, then see how long it takes to almost dry out. Thats how often you need to water. And yeah youll probably need a rockwool slab under your cubes, 3" isnt enough to support a plant, but it all depends on the size you want.
  3.  
    LoudBlunts

    LoudBlunts Well-Known Member

    so rockwool slab is like the foundation almost?


    sorta like what a brick foundation is to a manufactured/trailer home?
  4.  
    Muffy D

    Muffy D Well-Known Member

    I like the analogy. Yeah I guess you could say that. The slab is just something for the root mass to grow into.
  5.  
    mobby420

    mobby420 Well-Known Member

    I only want my plants to grow to about 2 feet, but already at 4 inches i see the roots comming out the bottom.... what happens if i dont put a slab underneath?

    do yo uthink the rockwool blocks will support 2 foot plants?
  6.  
    Muffy D

    Muffy D Well-Known Member

    do you just have the rockwool in the tray and nothing else? Many people put hydroton in thier tray so the roots will grow into that instead of a rockwool slab. The point is that the roots will die from the light if they dont have anything to grow into and that means the plant will only reach a certain size. Lets see a pic and more people will be able to help you out.
  7.  
    mobby420

    mobby420 Well-Known Member

    thats exactly what i was asking!!, thanks.... put some hydroton around the rockwell blocks for it to grow into... i heard hydroton is reusable also ? is it messy getting the roots out of there at the end of the grow? i know the rockwool i just throw away..... anything else besides hydroton? i would probally need allot to fill up the whole tray.... and wouldnt light still seep through the rocks? my tray is about 6 feet long by 2 feet wide...... I will be getting a digital camera soon :blsmoke:

  8.  
    mobby420

    mobby420 Well-Known Member

    another thing, is it normal for the tops of my rockwool blocks to be turning green ?

    I have allot of ventilation in the room, maybe it is because they have been being overwatered the past week?
  9.  
    Gyp

    Gyp Rogue

    you should get some panda film or something or cut up a trash bag, and make a cover to cover up any exposed rw to light. The green stuff is algae, and that's bad.
    I'd get those 6 inch rw cubes to put the 4 inchers ontop of. I and a few others are growing in strictly rw.
  10.  
    mobby420

    mobby420 Well-Known Member

    hmm, height is a bit of an issue for me.... so i think the hydroton and i will use the trashbag idea to cover it..... how do i get rid of the algae? whats causing it?

    can you tell me your experiences with rockwool? i think next time i will just use the bigger blocks to begin with!

  11.  
    Gyp

    Gyp Rogue

    I'm growing some sativas that can get to massive heights, if you watch any of the greenhouse seed videos on youtube, one of them was about 9 feet. I don't have that much height in my rooms. I'm just using the 4 inch rw on top of a 6 inch to keep the root growth down, which in turn will keep their height down. As far as killing the algae growth, I had a cube show signs, so I ripped the infected areas, I didn't notice any growth under what I ripped off, so I think that did the trick. If you can afford it, grab some hydroguard, it helps kill microbes or whatever they're called, add that into your res.
  12.  
    mobby420

    mobby420 Well-Known Member

    ive bough some hydroton, as well as hygrozyme..... i just changed the water and added half dose of nutrients, also i changed the watering schedule to only twice a day for 30 minutes each. i guess i will see in a couple of days how my plants are doing!
  13.  
    mobby420

    mobby420 Well-Known Member

    i rinsed the hydroton, but it still seems to be leaving a brown residue..... normal ?
  14.  
    Gyp

    Gyp Rogue

    yeah, it's the residue washing off, it's normal. I meant hydroguard btw, not hydroton, hope you knew what I meant.
  15.  
    potman5000

    potman5000 Active Member

    heres a tip u u dont want to grow in ur house and u gotta alota land t a plant then a corn plant then anotherplant trust me this works
  16.  
    mobby420

    mobby420 Well-Known Member

    Im having trouble with the ph, and intake of nutrients of my plants as well as not watering them too much.... I think tommorow i will test the ph of the water comming out of the rockwool instead of the ph in the resevoir....
    i just did some reading and turns out rockwool is not so ph stable..... even though i did soak it for 24 hours....
  17.  
    smokeandfly

    smokeandfly Well-Known Member

    not sure if any1 pointed this out cause didnt read it all but i grow in expanded clay and rw and i found for first say 3 weeks 1s a day was enough then go to 2 times a day for 3-6 weeks and now im on 3 times a day but im growing in expanded clay aswell as rw so u prob wont even need to water that much
  18.  
    mobby420

    mobby420 Well-Known Member

    thanks smoke and fly, no one told me, and well now im at once a day, i started out 6 times a day, realized it was wayy to much, went down to 3, then 2, now im at once a day, the rockwool really holds its water !!
  19.  
    hedgeskunk0258

    hedgeskunk0258 Member

    yep typicly dont have to water your rockwool more then once a day unless they for some reason get very dry well before the lights going to turn off and is neccesarry.(i use air cooled lights and heats not a problem at all my room runs at 78 f. if your room temp is high rockwool will dry out faster. remember your plant roots need oxygen to correctly use the nutrients your feeding your plants, so intale you want your rock wool, or grow medium to become dry (not bone dry but pretty dry) so your roots are exposed to oxygen while the lights are off. then water plants early(around when your lights turn on) so they can use up the water and nutrients efficientlly. im using fox farm soil at the moment and i only water every other day sometimes every three days. but im using five gallon pots. if using smaller pots say two gallons i find they become pretty dry after one day and usually water them everyday
  20.  
    andrewcovetsall

    andrewcovetsall Active Member

    View attachment 1371144 View attachment 1371143 View attachment 1371142 hey check this grow. i got my plants in 4x4 rockwool cubes. when i switched to flower, after 4 weeks of veg, i stacked another 4x3 cube underneath. everything looks good to me. o, dont let anyone say water here, or water there. it all depends on the size of ur plant and its ability to draw up the water u supply. i water 6 times a day. 5 times during lights on. for one minute at a time, except at night i let the water flush it for 5 minutes. i got a tray that runs my nutes back down into my rez to be reused. my journal explains better. heres a pic

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