OldMedUser
Well-Known Member
I surrender. You got it. PPM sux all hail EC.
When to begin nutes in rdwc
- Thread starter 420Mn
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Billy the Mountain
Well-Known Member
I can understand your confusion if your source of information is the Orchid Ninja from YouTube.
I would suggest a more authoritative source.
A good start would be Chapter 3 of Resh's Hydroponic Food Production
Bluelab has info re. EC vs PPM on their site.
"meaningless" - they're all proxies, at best, because different chemicals are taken up at different rates. I haven't read the book you've cited (thank you for posting that, BTW) but I got some insight into nutrient uptake rates from the paper "Principles of Nutrient and Water Management for Indoor Agriculture".
Oops, meant to cite "Nutrient Management in Recirculating Hydroponic Culture".
Waiting on the silica to be delivered, which may not be till saturday. The leaves are looking much worse today. Wondering if I should use peroxide as a foliar spray until it arrives? Peroxide is an antifungal.You've dosed a bit more of the CalMag I assume? It could be septoria but I'm not positive and not really sure what to do about it if it is. I would spray some dilute silica product especially on the undersides of the leaves to see if that helped as it wouldn't hurt. When I was doing DWC I always added some Rhino Skin which is AN's version of potassium silicate to my nutes and never had spotting like that. The only place I ever had that was on a big outdoor plant 7years ago or so and it didn't seem to cause any real problems so I did nothing. I brought that one in to flower but it spent 2 weeks in the shop under a 400W while it got sprayed for mites and thrips before it went down to the grow room.
I'd consider it mild septoria and treat as such myself or ignore it and maybe it won't matter but that doesn't always work.
OldMedUser
Well-Known Member
The BlueLab site says exactly what I've been trying to explain to the other guy. Same reading, different scales.
Case closed.
OldMedUser
Well-Known Member
You could try it but dilute your 12% 10:1 so you're just over a 1% sol'n. You might want to put a drop or two of dish soap in it so it evenly coats the leaves. And put some plastic cover over the hydroton tho maybe a spray on it would help if there are spores on it too. When I've sprayed for bugs I hit the tops of the rocks or soil to get any there without harm. Baking soda will also raise the pH and people use it for powdery mildew but it's not all that effective from the results I've seen in the past.
Sounds like septoria almost for sure.
I just sprayed with 3% right as your reply came thru. I will mix a new bottle of h202 @ 1% and add in a drop of dish soap (dawn) and hit them again later today. About to start the pool shock in a bit here, just waiting 24hrs since my last dose of peroxide as peroxide neutralizes chlorine.You could try it but dilute your 12% 10:1 so you're just over a 1% sol'n. You might want to put a drop or two of dish soap in it so it evenly coats the leaves. And put some plastic cover over the hydroton tho maybe a spray on it would help if there are spores on it too. When I've sprayed for bugs I hit the tops of the rocks or soil to get any there without harm. Baking soda will also raise the pH and people use it for powdery mildew but it's not all that effective from the results I've seen in the past.
Sounds like septoria almost for sure.
I will make sure to cover the hydroton as best I can when doing the second spray. Will probably use napkins as they will soak up any overspray and I have a shit ton of them.
Hopefully using 3% wasn't bad. I misread the directions online for mixing a foliar spray
OldMedUser
Well-Known Member
Have you noticed any reaction on the leaves since spraying with 3%? 3% does a slow burn on skin and I'd hate to see it fry your plants and that's why I mentioned a little over 1%. Skin turns white immediately when 35% gets on it but when washed off right away no real damage is done. Eye protection is a good idea even with 3%.
No burn yet but I had just applied it when you messaged me. After responding to your message I ran up to the grow room and used napkins to soak up the peroxide. I had only sprayed the infected leaves.Have you noticed any reaction on the leaves since spraying with 3%? 3% does a slow burn on skin and I'd hate to see it fry your plants and that's why I mentioned a little over 1%. Skin turns white immediately when 35% gets on it but when washed off right away no real damage is done. Eye protection is a good idea even with 3%.
Hopefully I did fry the plants, but the way things are going I wouldn't doubt it, lol
Which puts me in a predicament as the treatment for that is to remove infected leaves to stop the spread, which I can't do as they are important fan leaves. Hopefully the peroxide and the silica (when it arrives) does the trick. Not thrilled about it likely being septoria but I'm relieved to finally know what it is.
Not that I can see in this thread. What you have written in this thread on this topic is incorrect.The BlueLab site says exactly what I've been trying to explain to the other guy. Same reading, different scales.
Case closed.
You repeatedly state "Both EC and TDS pens measure the exact same thing but express it using different units.". That is simply wrong. EC pens do not measure PPM.
@Billy the Mountain has been quite precise and 100% accurate in what he wrote. I provided a citation that echoes what @Billy the Mountain wrote.
You assert "same reading, different scales" - that's not correct. EC is a measurement, the other values are calculations.
An EC meter measures electrical conductivity, hence the name. The EC meter will display the electrical conductivity value and it will convert that value into what's been referred to as "PPM".
@Billy the Mountain has stated this twice. What you have written is incorrect.
Seeing a reaction now. A couple of the leaves have tips curling upward.Have you noticed any reaction on the leaves since spraying with 3%? 3% does a slow burn on skin and I'd hate to see it fry your plants and that's why I mentioned a little over 1%. Skin turns white immediately when 35% gets on it but when washed off right away no real damage is done. Eye protection is a good idea even with 3%.
I can't seem to find your reply about spraying the plants with lights and fan off. How do I go about doing that? If I spray at night, after lights out, and turn the fan off, there will be no air circulation throughout the night, other than the inline fan. If I cut the lights for a period during the day/evening to spray, does the temporary change in light schedule risk triggering flower? Sorry if this is a dumb question, I just want to make sure I'm following the right procedure, unlike spraying the 3% h202 on the infected leaves, which i also did with the lights on.You could try it but dilute your 12% 10:1 so you're just over a 1% sol'n. You might want to put a drop or two of dish soap in it so it evenly coats the leaves. And put some plastic cover over the hydroton tho maybe a spray on it would help if there are spores on it too. When I've sprayed for bugs I hit the tops of the rocks or soil to get any there without harm. Baking soda will also raise the pH and people use it for powdery mildew but it's not all that effective from the results I've seen in the past.
Sounds like septoria almost for sure.
I woke up today to find the septoria had spread to the other plants. Made the decision to remove all the infected fan leaves from the crop. They were all shading bud site branches anyway so I figured it wouldn't be a bad idea to defoliate those and let some light in. The leaves were also blocking air circulation to the lower parts of the plant.
I spent hours today pouring thru the internet and every site says to use fungicide to treat septoria, or neem oil as an alternative. Although I trust in your advice and greatly appreciate it, you stated that you've never dealt with septoria and weren't sure how to deal with it, so I ordered a fungicide. Figure it's best to go with the tried and true method. I will definately be using silica as prevention in future crops as it provides many benefits to plants. Might even start adding it to the system with this crop for added protection. My only concern with silica is that branches can easily become too thick for LST training. That's why I chose not to order it when I ordered nutes.
OldMedUser
Well-Known Member
The way I do my spraying when needed is I have a power bar plugged into the timer for my lights. My circulation fan is usually plugged into a regular plug so it always has power but when I spray just at lights out I plug that fan into the power bar so it stays off until the light comes back on. By the time the light comes on the plants are dry and the air starts moving again. My exhaust fan has a temp/rh controller as well so I might turn up the rh side so the higher rh doesn't trigger the 6" exhaust as well.
You could just switch off the fan and lights for a couple hours during the plant's day cycle with no fears of triggering flowering. It takes a few days at least of shortened light period to trigger flowering in plants. If you are still worried about that you could leave a 9W LED light bulb, preferably a 5000K one, on during that short dark period as any light will be considered by the plants to be part of it's day cycle. Greenhouse growers will sometimes have a string of light bulbs around their plants to come on for an hour or so in the dark to prevent plants from flowering if the days are too short early in the season. Guys who start their plants indoors under 18/6 light use the same trick when putting them outside where there isn't a long enough day yet to prevent flowering. Doesn't take much light to keep the plants in veg mode.
Silica won't make the stems too thick to train. The tops are soft as they grow so very easy to manipulate. I've done a lot of ScroG grows and bend the hell out branches without breaking them. If the part of a stem where you want to make the bend seems too firm to easily bend you just roll it back and forth between your fingers to soften it up before bending. If one breaks as long as it's still attached you can always use a splint with a bit of masking tape to heal it. When my plants have got too tall for the lights I'll roll that stem and flop the top colas over and they often crack open but grow just fine and often bigger than if untouched. That's a good way to effectively top the plant without actually cutting off the top. Once the top is bent over lower than the nodes that are under it the plant reacts like it was actually topped.
New growth is very easy to have snap right off if bent just a bit too much. The fibers inside haven't toughened up yet so they can snap clean off. Tying them down and increasing tension over the period of a few days or hanging some weight on the end of a branch will get them where you want over time too.
A fungicide might be better and as you are in veg shouldn't be a problem. I just hate spraying what might be toxic crap on my plants if I don't have to.
Billy the Mountain
Well-Known Member
The pictures you posted look nothing like leaf septoria.
Leaf septoria is quite distinctive with "bullseye" spots of necrosis.
It's quite rare in indoor grows.
I'd do some research before blindly following advice in the future.
Leaf septoria:
Drop That Sound
Well-Known Member
Bluelab PENCON Conductivity Pen and Digital TDS Meter, Water Tester for Temperature and Nutrient (CF, EC, PPM 500, PPM 700), TDS Testing Kit for Hydroponic...
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Bluelab summed it up nicely. It all makes a little more sense now. Thanks.
amneziaHaze
Well-Known Member
Who cares.use ppm or ec in the end its just to compare todays values with yesterdays.you need just to see if it goes up or down soo you know is it nutes or water.
Did you ever think about using bacteria in your water tricoderma will get you rid of algea.
Dont know if it has any effect on seporia but i know they get sucked in the roots
Did you ever think about using bacteria in your water tricoderma will get you rid of algea.
Dont know if it has any effect on seporia but i know they get sucked in the roots
Amen! Leave it to a woman to be the voice of reason. Thanks for chiming in!
I did think about using southern ag (hydroguard alternative) but decided to run sterile.
I will prob try bacteria for the next run.