New to grodan (rockwool) and switching a light to test

Discussion in 'Hydroponics / Aeroponics' started by Slimjimham, Nov 29, 2016.


    LandAndHeir Well-Known Member

    I leach the medium with supernatural brand leach.their " flushing" additive. Then clean water for 2 weeks not anything special...comes out the tap @ 140 simple

    LandAndHeir Well-Known Member

    I keep my water at 67 no hotter or colder and I run sm90 and h202. Constantly. Warm water can let bacteria build and that is what I bet that smell is

    Slimjimham Well-Known Member

    ....I have chillers... I should just set it up to the res and keep it cooler... Do you find its necessary to also use aeration with air pumps or just water movement from the chiller?

    I'm running uc roots to keep it clean

    LandAndHeir Well-Known Member

    I don't have chillers. I live where it rarely gets warm

    mjinc Well-Known Member

    My last few grows I've used Rockwool only as the starter and then inserted them into hydroton. Was thinking of doing the same into coco but just growing in bigger cubes looks interesting. Do you have any worries about over saturation and what are those outside plastic cubes you have them in?

    Slimjimham Well-Known Member

    They come wrapped in plastic on the sides, the caps are floraflex caps... they're speed to prevent algae growth on top and reduce the cubes drying out from evaporation.

    I think this is the way to go... I typically grow trees, think I want to try growing some on slabs in the future to get some trees out of the rockwool

    Things are still going great... I see lots of people mentioning they grow dtw in rockwool... not recirculating.... anyone here do either of these methods and why

    Slimjimham Well-Known Member

    And I'm new to it but don't think I'll have issues with oversaturation... also the new blocks I bought are the pargro biggies 6x6x6

    They're supposed to drain 17% now meaning even drier conditions.... cheaper and made by grodan
    Blue brother

    Blue brother Well-Known Member

    you doing ok? Sorry been away a while.
    any problems ur having let me know and Il have a think
    Blue brother

    Blue brother Well-Known Member

    Slimjimham Well-Known Member

    So it looks like I've ran into a problem, my thought is that it's because ppm got too high or because blocks are not properly getting watered with my pump (upgrading from a 250 to 400-500gph per 4' x 6' table)

    Probably the ppm got too high, ph had been locked in at 5.8 the whole grow.

    On the white board #1 is the Rockwool grow... the first number is ppm on 500 scale.

    Basically each feed is 0ppm ro water brought up to 50ppm with cal-mag (MagiCal) then the rest of the ppm is Canna substrate a & b for soft water

    Also use uc roots to keep it sterilize but no ppm change with it.

    Anyways plants looked amazing up to the last pics I took on the 20th then pics on the 26th have deficiency... actual deficiency prob started right after the 20th but didn't document them... only thing that changed is ppm went from 700/800 ppm to over 900ppm which I'm thinking was too much.

    Anyways here are the whiteboard shots showing ppm, pics of healthy plants were obv the 20th... pics of deficiency were taken on the 26th and after

    20170201_153348.jpg 20170126_122554.jpg

    Any ideas??? Brought the ppm back down to 800 on 500 scale

    Thanks @Blue brother and everyone else who might have insight!
    Last edited: Feb 1, 2017

    mjinc Well-Known Member

    The light makes it a little difficult but the way it seems to effect the edges a lot more makes me suspect nute burn. Did you try a flush and check the ppm of the runoff?

    Blow4Life Well-Known Member

    Rockwool is king in my opinion. Sounds like you have everything figured out. I'd just say get away from using ppm scale and switch to EC. It's more accurate because different meters use different formulas to convert EC to PPM. You can run heavy food with rockwool. My EC is always between 2 and 3. That's like 1000-1500 ppm depending on math. And fuck ph. It's super overrated. I haven't checked mine in months. I change res every week. I start way low and let it drift all the way back up. Be sure you don't overwater. Try short 2 minute feedings 3 times a day to start. That guy Everest on YouTube has some great videos. Someone mentioned this earlier.

    Slimjimham Well-Known Member

    Hmmm, we'll I'm thinking the ppm is too high but by your standards it's too low. An 800 ppm feed would be a 1.6ec...

    I don't think it's due to over watering since it's 4x per day, cubes don't seem too heavy and plants loved the 4x per day watering only a few weeks ago

    Any input on why they seem less than perfect?

    Again I was thinking feed should be around 700ppm or 1.4 ec

    That's what the jungle boys mentioned they were feeding in flower...

    Any input and reasoning as to why they took a turn for the worse? I'm still thinking it was ppm

    GaiaGrower New Member

    Seems some are saying 2min. 3x per day but different pumps, number of drip lines, manifold settings, ect. Would effect flow rates. Looking for someone with long term ultimate success in veg and flower with blocks. Is it correct that with octibubblers set GPH is somewhat uninfected by pump pressure with the obvious exceptions of a pump to small to supply or one to large to burst fittings. Again looking for someone with long term success. For pump size, GPH and number of feedings per day with 6inch blocks, flora caps and octibubblers veg, and flower. Thanks in advance...

    Slimjimham Well-Known Member

    So an update, im still trying to learn every grow and get better. But im killing it! Shits looking better than ever and I've been at it a while. Check me out on instagram johndough207

    I'm looking forward to getting a grosens meter in the near future to really dial in irrigation

    Fuck recirculating though, drain to waste, and plants are happy happy!
    Blue brother

    Blue brother Well-Known Member

    I ran drain to waste for years before Recirc, unless ur constantly adjusting your ph in a dtw system ur not making efficient use of ur solution.

    Once I got good at dtw I was upping ph every other day, I’d start at 5.5 then up it to 6.2 over the course of a res. now I’m good at recirc I don’t adjust ph I just change res once it hits 6.2
    Blue brother

    Blue brother Well-Known Member

    Well done tho mate, sorry I haven’t been around for a year lol.

    baseless Member

    Yo man im growing in 6x6x6 cubes also. I just planted some clones, started out watering twice a day but now im thinking im overwatering. My question is what is your feeding schedule now that you have it running nice? I havent watered for a day and a half right now and my blocks are still heavy.
    Blue brother

    Blue brother Well-Known Member

    Water from the top every day with oxygenated nutrient solution, rock wool maintains a nice a balance of water/air no matter how often you water it. DOnt ever let it get dry though, this isn’t soil. You’ll see more problems by waiting for the plant to drink all the water as by the time it does the water is probably depleted of oxygen. Fresh oxygenated solution every day at least.

    Slimjimham Well-Known Member

    When I Transplant to 6x6 cubes I water on the transplant them dint water for like 10-14 days... feel the cube, it'll get lighter and when it feels like There's not a lot of water in there, then you water again... usually id say it's like 5-7 days after the second water that I water again....

    But your plants will tell you by the weight of the cube.

    Then when they go to flower I just water once a day for like 4-7days them up the watering to 2,3,4,5,6,7+ watering a day depending on how long tyre cubes hold moisture... if the cubes seem to be getting dry then I add in additional irrigation cycles ramping again from 1 to 7+ watering a day.

    Im using pargro quick drain so straight Grodan might take longer to dry down

    Again im sti new to this but this is what's working for me

    Check out my Instagram!

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