trouble forming roots w/ dwc

i have a 25 gallon tub with 6 5.5inch netpots, 100gph air pump with dual outputs leading to 2 12'' air stone stripes. 400 watt mh light 18'' from the top of the plants

since this is my first grow i've decided to just grow bagseed, i germinated the seeds then placed them into 1 by 1 rockwool cubes. i placed the cubes with the germinated seeds into my netpots. the top of RW is about 1/3 of the way down. at first i had phed 5.8 tap water about 1-2CM from the bottom of the net pot.



now the first 2 of the 6 plants have successfully developed into a good healthy plant with a solid set of roots and 2-3 sets of leaves. i planted them on OCT 5.1 of them is still growing strong but much slower than the second

now the last 4 started to wilt and then died sometime over the night. i tore apart the rockwool and found that there was a very sad root sytem growing. none of the 3 plants had a root system that was grown past the RW.

i just cleaned the res, changed the water today and added 1/4th strength of fox farm grow big for the remaining 2 plants...i'm going to make 2 5 gallon buckets for these so i don't waste as many nutes and ph up and down

i was wondering what could have caused this?

Most likely the culprit is genetics. When you're dealing with bagseed, there is a lack of uniform genetics like you get with a seedbank. Now, I have used the DWC method twice and never had any problems forming roots. From the sound of it, you did everything right. One thing you did not mention is what medium you used in the net pots. Did you use hydroton in addition to your cubes? What I did for the first week or so was make sure that the water level touched the very bottom of the net pots. That way, the hydroton would soak up a little bit of water and help the roots find their way to the bottom. After I could see the roots, I would lower the water level a little bit ( to an inch or so below the bottom of the net pots) so that the roots had to search for water. After that, I always had explosive root growth.

when you checked the rockwool on the ones that were dying was it moist or was it dried out

i use dwc myself and i find that with seedling or fresh rooted clones that it is best to let them get tall enough that u can place your rockwool cubes all the way to bottom of your net pots then fill with hydroton. then bring your water level up till it almost touches the bottom of your net pots. i do this because hydroton does not wick up water very well and causes the rockwool to dry out because the mist produced by your air bubblers cannot penetrate through the hydroton very well. once you see a nice rootmass coming out of the net pots you can then drop your water level down to about an inch from your net pots

JohnnyPotSeed1969 said:

Most likely the culprit is genetics. When you're dealing with bagseed, there is a lack of uniform genetics like you get with a seedbank. Now, I have used the DWC method twice and never had any problems forming roots. From the sound of it, you did everything right. One thing you did not mention is what medium you used in the net pots. Did you use hydroton in addition to your cubes? What I did for the first week or so was make sure that the water level touched the very bottom of the net pots. That way, the hydroton would soak up a little bit of water and help the roots find their way to the bottom. After I could see the roots, I would lower the water level a little bit ( to an inch or so below the bottom of the net pots) so that the roots had to search for water. After that, I always had explosive root growth.

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yea i use hydroton with the RW, and i did exactly what you do. after all my research i figured i better just use bagseed but since i have a feel for this now i might order some good seeeds now

grow1 said:

when you checked the rockwool on the ones that were dying was it moist or was it dried out

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the RW was moist, well at least the bottom 1/3 of the cube was moist the top not so much.

grow1 said:

i use dwc myself and i find that with seedling or fresh rooted clones that it is best to let them get tall enough that u can place your rockwool cubes all the way to bottom of your net pots then fill with hydroton. then bring your water level up till it almost touches the bottom of your net pots. i do this because hydroton does not wick up water very well and causes the rockwool to dry out because the mist produced by your air bubblers cannot penetrate through the hydroton very well. once you see a nice rootmass coming out of the net pots you can then drop your water level down to about an inch from your net pots

Click to expand...

these were not clones. but i see what you are saying. i think i'll make another one with a much smaller res.