brown roots? but not root rot!!!

[stinkyattic]

I am curious about the spreader material too, and the NFT/rw hybrid system you are running.
Can you post pics that show the system assembled, and how it all sets together? What is the spreader mat for in your system? How does it fit in?

On one hand a RW slab holds plenty of moisture and can be fed with a slow drip, or by ebb and flow bery effectively. On the other hand, you are running towards NFT. If that slab is sitting IN the NFT channel, it will be too wet, all the time.

I've seen leach trays that seem well suited to holding a RW slab ABOVE the NFT channel so that you can start out doing drip or flood until the roots are long enough to go into the channel, and then stop dripping and go true NFT. They are shown actually in the thread 'stinkys adventures in noob hydro' in 'grow logs' under 'basic growing', which is a hybrid NFT system, and was also finicky until the root system was established.

The trick with what I think you are trying to do is finding the balance between overwatering the slab and underwatering the protruding roots.

[beani1]

well the last 2 clones i had have now gone the same way. thought they looked alright but checked today and roots had gone brown under the blocks. it's strange though because on the first lot that did this i pulled all the brown roots off and now there are fresh white roots appearing! so they are still trying to grow, so im assuming that the plants themselves must be alright. i was beginning to think that the mother had picked up some sort of disease ( or has she? if you know of any let me know ). i'l give them another week to grow more roots and try again. ( i will not be beaten!!!!!) posted some more pics, same quality im affraid. it's a pretty basic set up, water get's pumped from the tank up to the growing level which is on a slope and then falls back into the tank at the other end. the spreader mat simply gives the roots something to grow into.and keeps them moist when the pump is not on.

[gainesvillegreen]

The cutout you made in the third picture, for light protection, is it very light-tight? If too much light is getting through either at the cutouts or on the perimeter, it could indeed cause the problem you are having.

I would still tell you to add an active form of aeration for your nutrient solution. My best guess on your problem is inadequate oxygenation of the roots. Fork out the $10 for a pump at wally-world and another $4 for some air stones. Put those in your reservoir and let them run 24/7.

Another thing you might try, if you have any more plants not attached to the nutrient film, is to remove one plant and set it on a plate out of the system. Water it a couple of times a day to keep the rockwool moist and see if the roots do any better.

[beani1]

there's two covers. there is a black one under the white one which has been cut in this way X so that each corner sits on top of the block and stops any light getting to the roots. you can just see it on the third pic. the white one is purely for reflection . i have put an extra pump in the tank which just feeds back in resovior near the main pump. it makes a lot of splashing noise though!!!!! all the plants i have taken out of the tank and stripped of brown roots are all rooting again, so next time i intend on only running the solution once or twice a day.

[stinkyattic]

Try running without the spreader. My instinct says the root of the problem (har har har) lies somewhere between the block and the tray... roots will naturally grow to the best area available to them, and don't need guidance.

[beani1]

yea i have thought about that myself. but then i would have to run the solution more frequently to make sure the roots do not dry out.

[beani1]

good news i have now got an air pump for free!!! bad news is i got it from my local grow shop because they are closing down and moving abroad. shame really because they are really nice people.