brown roots? but not root rot!!!

[beani1]

have nft.canna aqua vega 1.2 cf, ph 5.8, tap water ( been tested ok ). about a week after being put in the tank the roots under rockwool block turn a sort of translucent brown and are weak, but do not go mushy, roots outside of block are white but eventually go the same. plants still take up water, but growth is very slow. stem go's purple and older leaves, then others yellow suggesting slow,or no neut up take. everything is always sterilised and rinsed, but this has happened 3 times in a row. please refer to before and after pic. can anyone PLEASE help.

beani1 Reviewed by beani1 on 01-16-2008. brown roots? but not root rot!!! have nft.canna aqua vega 1.2 cf, ph 5.8, tap water ( been tested ok ). about a week after being put in the tank the roots under rockwool block turn a sort of translucent brown and are weak, but do not go mushy, roots outside of block are white but eventually go the same. plants still take up water, but growth is very slow. stem go's purple and older leaves, then others yellow suggesting slow,or no neut up take. everything is always sterilised and rinsed, but this has happened 3 times in a row. Rating: 5

[Dro_blower]

what type of buckets you have them in? if they are not light proof then light gettin to the roots may cause them to die out like yours

[beani1]

roots are covered in nft tank

[gainesvillegreen]

Fill out the troubleshooting form at the top of the forum. Most importantly for your problem, we need to know how you are aerating your nutrient solution, what your nutrient solution is, what the pH is, and what the temperature of your nutrient solution is.

Fill that out so we can help you.

[beani1]

-indoor
- hydroponic
-specific medium: rockwool block
-Soil type/brand: n/a
-Hydro
-Anything you have added to the soil:n/a
-Soil pH:n/a
-Water source: tap water/ recenly tested
-Water pH:5.8
-Age of plant: 1 month ( mother 7 months )
-Type of fertilizer: canna aqua flores
-Rate of application: have tried constant and every 3 hours
-Lighting source and distance from plant 600w son t/ 1 1/2 foot
-Temperature (both day and night if you are running a dark period) day: 30 degrees/night 20 degrees
-% Relative humidity: 50
-Lighting schedule18/6
-Type of ventilation your room has: intake from open window ( not good i know, but not my house) rotating fan and extractor.

[beani1]

not sure what nutrient temp is, but it is not cold.

[gainesvillegreen]

Well, the first picture has roots that look perfect and the second picture looks like they've become desiccated. What is the white material/background in the second picture?

How do you apply your hydroponic nutrients? Does the NFT mean nutrient film technique? Your problem has to be one (or more) of the following: light contacting roots, insufficient oxygen in your nutrient solution, pH of nutrient solution, chemicals in nutrient solution, or pests.

Could you guess on the nutrient solution temperature? If it is too low it will shock the plants, too high and it will not hold the necessary oxygen.

[beani1]

the white material is the spreader mat, yes it is nutrient film tech. i don't think it's light because the roots go brown under the block first . roots inside block seem to be strong and healthy. been to my local hydro shop and they say that the solution should be adequately oxygenated in my system. but i have been adding liquid oxy (ie oxy plus) at 5ml per 10 litres. i also add pythoff. ph of solution is 5.8.
solution temp if i had to guess would be room temp/ tepid but not warm. when you say desiccated do you mean dry? because they don't feel dry. as i have said i have discussed my problem with my local hydro shop and they are totally stumped!!!

[gainesvillegreen]

I'm almost out of ideas. If I had to take a guess, it would be root oxygenation. You mentioned the local hydro shop said the solution should be adequately oxygenated, how are you oxygenating it? Are you relying on falling solution to churn? or do you have a pump aerating it? You also said that you add liquid oxy, so I'm assuming thats H2O2. 5ml per 10 liters would not be enough to oxygenate your solution by itself, so I'm still leaning towards 02 supply.

Can you take us some more pictures? Some duplicates of what you already did, in better quality would help. Maybe a few of your whole setup as well.

[beani1]

i was relying on falling solution to churn as it entered the plant section. but know i have put a hole in the deivery tube so some of the solution falls back into the tank getting aerated then being pumped into plant section. i will also put a spare pump i have in just to aerate the water near main pump. as for pics i only have the phone cam, and only 2 plants in the system which have just rooted to the spreader mat, so i don't really want to disturb them as the roots seem to look ok at the moment. i'l see what happens over the weekend and let you know on monday.