So I have been experiencing a mysterious yellowing for about 10 months. Every thing that went into one of my 11 different rooms (some that had been going 5+ years) started to yellow and eventually die. My first instinct was my ph I checked my pens, they were not very far off but I calibrated and bought new probes anyways. That did nothing. Then we suspected the nutes, maybe we got a bad batch. I had bought 6 gallon jugs and filled all my 1 gal’s up off the same batch. Call the company run the batch numbers and they say they are 18 months old, So we went out bought new nutes and nothing changed. So after that I figured my favorite brand had fallen off and we decided to try another brand. We go buy $1000 worth of canna. And we thought possibly it could be something with our clones so we picked up a batch of clones from an LA club. Same thing new nutes new genetics same yellowing. So now I am scratching my head start making some calls visit a bunch of other rooms, and at least 20 in my immediate area have this same mystery problem. So I do some research find out we are all on the same water supply. I found 4 rooms on another water district doing bitching so I say BINGO, It must be the water. We go out and buy a 275 gallon tote and start buying water from this other district. A real pain in the ass I might add we had to do 2-3 trips a week to meet our demands. Same problem. We start doing testing 1st water test, 2nd tissues sample, I have a horticulturist come and look at things. He suggests an Iron def. We get our tests back everything looks good. We do a tissue sample off a room that is doing good compare our results and everything is fine. Except my plants still look like shit. So I emailed my test results to my original nute company they pass it around the office and let everyone take a look at it. I get a call a couple of days later from them and he asks me if I have ever considered off gassing. What is crazy is the night before I found a thread on the hydro huts and was showing my partner how Identical it looked. So now we go to our rooms and start looking around at what it could possibly be. Like I said some rooms had been going in the same location with nothing changed in about 5 years. There is only 1 new product that we had replaced the ½ tube that connects all the buckets. I started to call around and every room that was having the problem had replaced there tube with the new stuff. The 4 rooms that were doing good were using old hose and was just washing it out. So being lazy saved theses guys who would of thought. I have been talking to the company that made the offending tube for 4 months and they do not wish to resolve this problem even though I have proof that the toxic chemical is in the tube. We have done GC/MS testing, LC/MS, testing and FT IR testing that show conclusively that the chemical Diisobutyl phthalate is in the tube. This is the same chemical that caused the problems with the hydro huts. If you are having a mysterious yellowing and are using NGW tube replace it immediately and please respond to this thread. I am going to be working on a class action against these guys. I have some of the worlds top experts on the matter willing to testify and do any research needed to win this case. The idiots printed there names on the tube it has n-g-w.com printed every foot, so it is easy to identify.
Here is a brief description of what the phthalate does to the plants.
The toxicity caused by a volatile constituent from certain samples of flexible polyvinyl chloride (PVC)
was due to dibutyl or diisobutyl phthalate (DBP or DIBP) plasticisers. It has caused serious financial
losses in the horticultural industry. The two phthalate esters have low volatilities, so any toxicity lasts
for many years. Radish (Raphanus sativus L. cv. Cherry Belle) seedlings, exposed to an air stream
containing 160-180 ng dm~3 of butyl phthalates developed chlorotic leaves within 3-4 d and died
within 12 d. Neither dioctyl nor diisodecyl phthalate (DOP nor DIDP) produced damage in the test
plants. Measurements of photosynthetic and respiratory gas exchange in intact shoots of affected
radishes showed that photosynthesis was severely inhibited whilst respiration was virtually
unaffected. Electron micrographs of sections from young leaves showed disruption of thylakoid
formation and granal stacking. In mature leaves, thylakoids and grana were well formed but
chloroplasts were swollen and the thylakoids were pushed towards the vacuolar side of the
chloroplast. Sensitivity to toxic phthalates varies between species; all members of the Crucifcrae tested
were susceptible, tomato less so, and lettuce and ryegrass were resistant. Toxicity of DIBP, from PVC
glazing strip, caused a reduction in crop value of £20000 per acre per year in commercially grown,
The effects of phthalate esters on chlorophyll a2 fluorescence in radish plants (Raphanus sativus L. cv.
Cherry Belle) were examined Fluorescence yield was increased in those plants exposed to an aerial
concentration of 120 ng dm"3 dibutyl phthalate (DBP) at a rate of 3-0 dm3 min"1 for 13 d.
Comparison of fluorescence enhancement ratios and Fr^/F01 suggests that DBP inhibits photosynthesis
in radish plants at a site after QA. Both DBP and diisobutyl phthalate (DIBP) strongly
inhibited uncoupled (PS2 + PS1) electron transport rates in thylakoids isolated from spinach. At a
chlorophyll concentration of 10 /ig cm"3 the concentrations of DBP and DIBP exhibiting 50%
inhibition were 44 mmol m " 3 and 42 mmol m " 3 respectively. Basal electron transport rates were also
inhibited, with 87 mmol m"3 of DBP or DIBP producing 50% inhibition. Measurement of
photosystem 1 activity suggested that the main site of action of these phthalates was localized at a site
near the reducing side of photosystem 2.
The analysis of the samples has been completed and the results are given below. The sample information is:
______________________________ ____________________ ________________
Customer Identification: PVT Tube
Sample #: 10281a
Date Received: 7-12-10
Test Requested: Identification and Quantification of Phthalate(s)
USP <851> FTIR with quantitative extraction.
FTIR spectrum matches well with diisobutylphthalate library spectra and reference standard.
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