Hello friends . These ppfd numbers which there are around internet dont work for me . They said for example 150-300 ppfd for seedling stage , 200-400 or even 600 for veg stage etc. Every time i try to catch these numbers my plant stress. I ve par meter and a led zeus 600w pro 2.9 . For example, in a plant 1 month and 10 days old from seedling (now in veg) if i give it more than 200ppfd it will be stressed . Are these numbers only marketing or i do something worng??
ppfd / par
- Thread starter geogro
- Start date
Ca++
Well-known member
I tend to run seedlings lower, and then veg around 300, which seems ample. 600 is firmly into flower territory.
As daily light accumulation is tied to the illumination at any one moment, that number of hours the lights are on, are important. I use perhaps 300 in veg, but 24/7 not 18 or 20 where 400ppfd might offer a similar daily light accumulation.
Daily light accumulation, is a layman explanation. It's proper term is DLI or daily light integral.
Try running at the low end of the suggested ranges. Maybe 100 for seedlings. 200 for veg. 500 for bloom. Some plants do well at lower light, and don't want high light. In any case, lower light is easier on the plant. As you increase it, the grow gets more demanding of other aspects needed to support higher growth rate.
Lower light will be more forgiving. Find what works, then try edging forward to see what's actually stopping you going further. Some pics of the unhappy plants would be very useful
As daily light accumulation is tied to the illumination at any one moment, that number of hours the lights are on, are important. I use perhaps 300 in veg, but 24/7 not 18 or 20 where 400ppfd might offer a similar daily light accumulation.
Daily light accumulation, is a layman explanation. It's proper term is DLI or daily light integral.
Try running at the low end of the suggested ranges. Maybe 100 for seedlings. 200 for veg. 500 for bloom. Some plants do well at lower light, and don't want high light. In any case, lower light is easier on the plant. As you increase it, the grow gets more demanding of other aspects needed to support higher growth rate.
Lower light will be more forgiving. Find what works, then try edging forward to see what's actually stopping you going further. Some pics of the unhappy plants would be very useful
There are two rules of thumb when using fertilizers. One is to use a high concentration with 20 % runoff every few waterings or low concentration with no run-off with every watering. .
I just use 1/3 of the manufacturer's recommendation. I keep the same ratio as the table says, but add it to 3 gallons instead of 1 gallon. The frequency can be increased or decreased according to the soil needs. If I get a reading from the soil that's low I add low ppm without discharge and build the ppm up. IF my EC get too high I allow runoff to lower the EC. If you use high concentrations of fertilizer you have to have a run-off to keep the EC from getting too high.
I just use 1/3 of the manufacturer's recommendation. I keep the same ratio as the table says, but add it to 3 gallons instead of 1 gallon. The frequency can be increased or decreased according to the soil needs. If I get a reading from the soil that's low I add low ppm without discharge and build the ppm up. IF my EC get too high I allow runoff to lower the EC. If you use high concentrations of fertilizer you have to have a run-off to keep the EC from getting too high.
Are these limits so stricted ? I mean if temp and RH were a bit higher i could give them from 200 to 300 ppfd ?Is it so crusial even if for these little changes?
Light on 18/6 . My substrate is soil biobizz allmix . I dont stuck so much with the ph , only most of times i correct it around 6-7 cause my tap water is over 8 .
May i need to push them with more nutritients to support higher light intensity ( i search about that and it is a bit tricky and confusing ) .
Light on 18/6 . My substrate is soil biobizz allmix . I dont stuck so much with the ph , only most of times i correct it around 6-7 cause my tap water is over 8 .
May i need to push them with more nutritients to support higher light intensity ( i search about that and it is a bit tricky and confusing ) .
IF your plant looks good then keep it steady without any major changes. Consistency is very very important and if you play around with the nutrients trying to boost the plants, you can run into problems. If more light brings up the temperature then adding more nutrients can hurt the plants. When it gets hot the plant transpires more water and more water means more solute to for the plants to process and that raises the salt level in the plants.. They look great now just leave them alone and let them do what they do best.
When one gets dialed in and knows what they are doing. Newcomers should keep it simple from the beginning and advance with a few cycles. No need in trying to squeeze blood out of a turnip. Easy with the fertilizer in the beginning because you and always add some later if the plants need it. No need in giving a plant fertilizer if it is healthy and has all it needs. Plus anyone telling someone to put fertilizer on their plants without knowing the person's soil chemistry is acting irresponsible.
Vandenberg
Well-known member
geogro, Welcome! to the ICMAG forums, you just received some great advice.
Others will read this and benefit too.
Good luck with your grows.
Vandenberg
Others will read this and benefit too.
Good luck with your grows.
Vandenberg
Ca++
Well-known member
45%-50% RH is low. People don't tend to run such numbers until their is a mold risk in the final weeks. Moving to 60% is where the action is. The pores can open and get some more co2, while fluid movements within the plant are not so throttled. This higher RH leads to better conditions, that can support more light.
The ppfd numbers you are looking at are not for co2 enrichment. It would be a waste of gas. It generally is, and it's in short supply right now. People are purposely making it, rather than catching a byproduct. co2 production for wasting straight into the air is crazy.
I tend to stop advising co2 users. That's just how I feel about it. You can do perfectly well without it. I'm not an environmentalist. It's just not helping anyone.
The ppfd numbers you are looking at are not for co2 enrichment. It would be a waste of gas. It generally is, and it's in short supply right now. People are purposely making it, rather than catching a byproduct. co2 production for wasting straight into the air is crazy.
I tend to stop advising co2 users. That's just how I feel about it. You can do perfectly well without it. I'm not an environmentalist. It's just not helping anyone.
Week 4
Active member
Some strains are just sensitive to LED lighting. (I'm guessing your using LED Lighting here, am I right?) Anyways, raise it to 30 inches, and are you using tap water or RO filtering? I read an article that suggested this could be a Magnesium thing but everyone here is right about checking your pH first before adding or subtracting anything.
Another thought is get some air movement in your environment. And if there is movement maybe point the fans away from those troubled areas.
That 60% suggestion is a good one and very easy to do. I had the exact same thing going on and most of it went away after raising the lights up to 30 inches from the ladies. And adding some Epsom Salts (1 tablespoon to gallon) changes don't happen over night so don't chase your tail if you don't see an immediate change the next day (lets check back a week later and see how they're doing. . Your plant looks healthy otherwise.
- Soil – 6.0-7.0 pH
- Hydro/Soilless/Coco – 5.5-6.5 pH
Another thought is get some air movement in your environment. And if there is movement maybe point the fans away from those troubled areas.
That 60% suggestion is a good one and very easy to do. I had the exact same thing going on and most of it went away after raising the lights up to 30 inches from the ladies. And adding some Epsom Salts (1 tablespoon to gallon) changes don't happen over night so don't chase your tail if you don't see an immediate change the next day (lets check back a week later and see how they're doing. . Your plant looks healthy otherwise.
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Ca++
Well-known member
I wasn't being selfish. Perhaps I could of worded it differently though. My use of co2 would negatively effect the entire planet, thus, how is it helping me. Instant gratification for one person at the expense of others, isn't helping anybody. Even me. I'm not that short sighted.No offence but CO2 doesn't help anyone?
Mmmmm gassssy
View attachment 18761581 View attachment 18761583
The accepted record for grams per watt wasn't using co2.
I see no relevance in these pics. Somebody used co2 to grow some plants you can see the floor through. I think I should post your pics as proof it's not useful?
Nice garden lemonade .Thank you all for your replies . I decide to stuck more with vpd and a better way to introduce more light on my plants .
Co2 i think its usefull when you ve already reach the normal limits and you want go further . Now i ll try to catch even the lower limits...
Co2 i think its usefull when you ve already reach the normal limits and you want go further . Now i ll try to catch even the lower limits
...
Three Berries
Active member
If you had a sealed environment with good CO2 control then it would be converted to plant mass, as would any excess anyway somewhere. Not hard to maintain 1500 ppm in a room.
Three Berries
Active member
I had to dial back my 300w flower LED as I have potassium issue otherwise. And I've seen seedling stunt and not do anything from too much light. In Veg I can get away with all they can take as long as I feed them the Ca, especially with higher CO2.
Just set up a seedling tent with a 50 w light for the next grow of a couple autos today. Seem to have some flower congestion as two tents are now in flower. I'm thinking of cutting the main colas off the mature ones and letting the smaller buds go for two or three more weeks. I have the time now.
Just set up a seedling tent with a 50 w light for the next grow of a couple autos today. Seem to have some flower congestion as two tents are now in flower. I'm thinking of cutting the main colas off the mature ones and letting the smaller buds go for two or three more weeks. I have the time now.
Week 4
Active member
"if"
