Just wanted to spread the word. I just started growing a single photoperiod (gasp!) NYC Diesel a few weeks ago (only one plant for a variety of reasons), and everything was going great. I had upgraded my setup pretty dramatically (water chiller, added an inline UV sanitizer, decided to go for a sterile DWC instead of semi-organic with beneficials), and all was going perfectly for about 2 weeks. I noticed growth seemed to slow, then pretty much stopped, the leaves that were already grown were looking OK, but very stunted growth, but there was almost NO new growth coming from the primary growth tip. I also had some deformed leaves, which made me think maybe it was a pH problem, but every time I checked, it was perfect at 5.8.
I recalibrated my pH meter no less than 3 times, checked my nutrient levels (right around 150 ppm, right where I'd want it for a seedling having health issues), and was scouring the internet for what the issue might be. I changed the water twice I think, and noticed slight improvements each time I gave it a fresh batch of nutrient water, but then back to the same old issues.
After running through all the possibilities (maybe it was the off brand expanded clay pellets releasing some bad chemical? maybe it was the new material from the hose releasing something? or the chiller? or was I chilling the water too much? maybe these cheap lowes buckets are causing some issue?) and comparing pictures of every nutrient deficiency there was, I was at a loss. Then, the other day, in a stroke of sudden realization, I thought, holy crap, I wonder if the UV light is doing bad things to my nutrients? I know UV light damages just about everything, and the nutrients in solution can be delicate. So I went right back onto the internet, and searched for bad stuff happening with UV lights.
Lo and behold! There is a known issue with UV lights! It makes something around 100% of iron unavailable through a process where the light breaks down the chelation material, rendering iron not soluble and nearly impossible for the plant to take up (it ends up precipitating out of solution as iron oxide). I'd also be willing to bet that it un-chelated more than just iron, but looking at my symptoms, it looks more and more like an iron deficiency, which makes sense. I was running the UV light on the same timer as my main light (18 hours a day), whereas I was reading about some people who would run it for say, only half an hour a day.
So now for the past two or so days, I've kept the light off, and changed the water one more time, and already it's growth pattern has changed. You know how usually the plant seems to barely be able to get out of it's own new growth's way? Kind of like a fountain of new leaves coming out of each main growth tip? It's finally looking like that again, which makes me much happier. I'm sure I'm going to see that explosive growth DWC generates in another day or two as it finally gets the nutrients it needs.
So moral of the story is, don't waste your money/time setting up a UV sanitizer. It unbalances/ruins your nutrient solution. The worst part for me was the fact that the piece of crap sanitizer I got leaked like a sieve out of the box, and it took me about three or four days of fiddling with it and buying fittings that were actually watertight to finally get it to stop leaking. And now it's just going to sit there, in line, not turned on for the rest of the grow, just in case I DO get some root rot or other infestation.
Hope this helps some of you folks out there! And if you want some more information about it, I'm sure I can backtrack and find my sources. Cheers!
I recalibrated my pH meter no less than 3 times, checked my nutrient levels (right around 150 ppm, right where I'd want it for a seedling having health issues), and was scouring the internet for what the issue might be. I changed the water twice I think, and noticed slight improvements each time I gave it a fresh batch of nutrient water, but then back to the same old issues.
After running through all the possibilities (maybe it was the off brand expanded clay pellets releasing some bad chemical? maybe it was the new material from the hose releasing something? or the chiller? or was I chilling the water too much? maybe these cheap lowes buckets are causing some issue?) and comparing pictures of every nutrient deficiency there was, I was at a loss. Then, the other day, in a stroke of sudden realization, I thought, holy crap, I wonder if the UV light is doing bad things to my nutrients? I know UV light damages just about everything, and the nutrients in solution can be delicate. So I went right back onto the internet, and searched for bad stuff happening with UV lights.
Lo and behold! There is a known issue with UV lights! It makes something around 100% of iron unavailable through a process where the light breaks down the chelation material, rendering iron not soluble and nearly impossible for the plant to take up (it ends up precipitating out of solution as iron oxide). I'd also be willing to bet that it un-chelated more than just iron, but looking at my symptoms, it looks more and more like an iron deficiency, which makes sense. I was running the UV light on the same timer as my main light (18 hours a day), whereas I was reading about some people who would run it for say, only half an hour a day.
So now for the past two or so days, I've kept the light off, and changed the water one more time, and already it's growth pattern has changed. You know how usually the plant seems to barely be able to get out of it's own new growth's way? Kind of like a fountain of new leaves coming out of each main growth tip? It's finally looking like that again, which makes me much happier. I'm sure I'm going to see that explosive growth DWC generates in another day or two as it finally gets the nutrients it needs.
So moral of the story is, don't waste your money/time setting up a UV sanitizer. It unbalances/ruins your nutrient solution. The worst part for me was the fact that the piece of crap sanitizer I got leaked like a sieve out of the box, and it took me about three or four days of fiddling with it and buying fittings that were actually watertight to finally get it to stop leaking. And now it's just going to sit there, in line, not turned on for the rest of the grow, just in case I DO get some root rot or other infestation.
Hope this helps some of you folks out there! And if you want some more information about it, I'm sure I can backtrack and find my sources. Cheers!
