Led Users Unite!

Randomblame said:

They look fine for 31 days in soil. That they look so squat is due to the high proportion of blue light. That changes when you shorten the day length to 12/12h in a few weeks.

450w true watt would be "way" to much for a 2x 2', but as far as I know one Mars300 is only 180w at the wall and the small 150w one is maybe only 70-100w or so. I would buy a 10$ kill-a-watt meter or another wall watt meter from walmart.

200wall watts blurple (or ~50w/sft) should be more than enough for a 2x 2' area. You have already 250-280wall watts!
What's the distance to the lights currently? It could be neccessary to keep them 20-24" above the canopy to avoid damage. Temps should be near 30°C/85°F with humidity just below 60% when lights on, and <50% when lights off.
Is there a way to disable the veg switch on one of the lamps? This would deactivate a few the unwanted blue diodes and would reduce the power a bit so you get closer to the 200w mentioned above.

Click to expand...

Unfortunately there is no veg/bloom switch on these. The ufo 150watt which I think is 75 true watts seems to be more for bloom as it has more red. I believe the lights were to close. Around 14 inches from plant. I moved both to 24 inches. Also, my temps are consistent around 78-84. My humidity is an issue. It's between 20-35. The next step would be to invest in a humidifier? Thanks for the help!

Darr26 said:

Unfortunately there is no veg/bloom switch on these. The ufo 150watt which I think is 75 true watts seems to be more for bloom as it has more red. I believe the lights were to close. Around 14 inches from plant. I moved both to 24 inches. Also, my temps are consistent around 78-84. My humidity is an issue. It's between 20-35. The next step would be to invest in a humidifier? Thanks for the help!

Click to expand...

Quick solution for the humidity in the meanwhile: Soak a couple sponges to the point where they're not dripping wet, but they're holding water (so not too wet), and just leave them in your grow room. Humidifiers can be as complex as you want (commercial units) or as simple as you'd like (sponges releasing moisture into the atmosphere) At the least, if you still decide to purchase a humidifier, this'll help in the time between now and then.

It's an old guitar trick to keep expensive guitars' wood from drying out

Tejashidrow said:

@Darr26
Good monring!!!
I have grown with mars300
130 watts at the wall is what is advertised
I had 118 watts from the wall
Still, properly set up will grow fine.
I have a veg/bloom switches on mine but Allways kept it in bloom mode.
If you get them too close the lights color will not blend.
Too far away and loose intensity.
12-16 inches away was my sweet spot.
HOWEVER
I grew scrog with them and had a even canopy.
Your tent will heat up with these make sure you have good airflow
While the footprint they claim will grow plants, the sweet spot for flowering is much smaller.
Some of my best grows were achieved with a mars hydro blurple.
Once you understand the mars hydro limitations, you will then start to achieve your goal.
I have not used your other light so I agree with @Randomblame about its wattage
Guesstimating :
Say 125watts for the hydro
65 watts for the other
Just under 200 watts which is good for your size tent
The Kill-a-watt meter is a great investment for $10
(Mine cost more cuz I got it years ago)
Ooops I was mistaken
My mars hydro reflector has the switches
My mars 300s don’t

Grow well!!

Click to expand...

Thanks for the tips!!! Appreciate the info!!

Darr26 said:

Thanks for the tips!!! Appreciate the info!!

Click to expand...

Actually, thinking now, what about if you misted the walls with moisture in the meantime? Like, with a spray bottle. You may want another member's opinion on this, too, I think, for any safety precautions I'm not thinking of

Moflow said:

Meanwell HLG 80H 36 or the Hlg 120H 36 maybe?

Click to expand...

They actually make an hlg-100h-36a or b

samlant said:

Quick solution for the humidity in the meanwhile: Soak a couple sponges to the point where they're not dripping wet, but they're holding water (so not too wet), and just leave them in your grow room. Humidifiers can be as complex as you want (commercial units) or as simple as you'd like (sponges releasing moisture into the atmosphere) At the least, if you still decide to purchase a humidifier, this'll help in the time between now and then.

It's an old guitar trick to keep expensive guitars' wood from drying out

Click to expand...

Right on thanks man! Going to try that right now!

samlant said:

Actually, thinking now, what about if you misted the walls with moisture in the meantime? Like, with a spray bottle. You may want another member's opinion on this, too, I think, for any safety precautions I'm not thinking of

Click to expand...

I've actually been trying this but it doesn't seem to bring the humidity up to much. I have also tried a couple cups of water

Darr26 said:

Unfortunately there is no veg/bloom switch on these. The ufo 150watt which I think is 75 true watts seems to be more for bloom as it has more red. I believe the lights were to close. Around 14 inches from plant. I moved both to 24 inches. Also, my temps are consistent around 78-84. My humidity is an issue. It's between 20-35. The next step would be to invest in a humidifier? Thanks for the help!

Click to expand...

Is the outside air already so dry or is it just so dry in the tent? What exaust ventilation do you use?
Most inline fans can be dimmed. I had to dim my exaust fan down to 15% to maintain an acceptable humidity.
Cheap exaust fans may start to hum when dimmed via PWM. If this is the case, use a step transformer that reduces the voltage. I own a 5-step transformer which allows me to dim between 15, 25, 50, 75 and 100%.(100-230v)

Another tipp!
Place the sponges in front of the fan, or better place a big bowl of water in the tent and place a fan on top. Moving air across the water surface will multiply the evaporation and you only need to refill the bowl! A flat bowl with the largest possible surface or a roasting pan or a plastic pan. Each large-opening container should work. Side effect, you cool down the ambient air a bit.
You can also put one or two piezo elements in the bowl or pan to create some light mist.
(Those with 12v, as they are often used in indoor fountains. You can get them for 2 bucks or so from e3ay/am4zon)
That would increase the evaporation rate so that you might be able to do without a humidifier.
However, it is important that you can dim the exaust fan to keep the moisture in the tent. For now, I would recommend turning it off temporarily with a timer. 5 minutes on, 5 minutes off maybe..

This one below is able to mist up to 350ml water per hour. It's the first one siutable I found but it already includes a 24v driver. Not the cheapest, but for sure cheaper like a humidifier. 350ml/h is a lot, I believe it's not neccessary to let it run all the time. Fan and mist element could be run on the same 12v driver when you take one with 12v and a cheap humidity controlled switch(like a Sonoff TH10, 9$) could switch it on and off like neccessary.

https://www.ebay.com/itm/Ultrasonic-Mist-Maker-Fogger-Water-Fountain-Pond-Atomizer-Air-Humidifier-NO-LED/142633235468?hash=item21359a740c:m:mT4d1jyC9BNsbUrsQJL7JLA&var=441609793853

Here are a few with 12v(pure PCB and mist elements)
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313.TR7.TRC2.A0.H0.XUltrasonic-Mist-Maker+12v.TRS0&_nkw=Ultrasonic-Mist-Maker+12v&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=humidity+switch+module+display&LH_TitleDesc=0

Just a note on humidity levels and measurements: it is very, very hard to get an accurate reading on humidity. Even expensive, $1,000 instruments won't be extremely accurate. In fact, calibration devices themselves struggle, even within controlled laboratory environments as they are hard and difficult to manage. When we have a <$200 instrument measuring the humidity, when it shows RH as 60%, what it really is saying is 56-64%. We must think of humidity as a range, even despite the tools (such as a hygrometer) outputting a single number (55, 35, 46, etc.). Moreover, when it says 60%, such as in the example, and the range we put it in is +/- 4%, it is most likely that it is within the lower range (56-60%) due to the resistance that grows when the tool measures farther out than 50% (ie. most tools are less accurate the farther out from 50% you get due to increased resistance). Lastly, Ive seen quite a few praises for instruments that (1) give fast readouts and, (2) give the same readings as other humidity-measuring tools when put side-by-side. The 1st may not be a desired trait for our growing purposes and the 2nd is not a valid metric at all. This has to do with sensitivity. We may not realize it, but our bodies have A LOT of influence on what the humidity levels are. These tools are so sensitive that even the moisture from our breath, the heat of our palms as we hold the instrument (for example, a Caliber 3 or 4) and even our very presence (the moisture from our skin) will yield different results. Also, different room dynamics and spacing and distances from moisture sources, etc etc. This (and a lot more related to airborne particles and various gaseous molecules in the air) is what causes the differences in RH measurements when we place hygrometers next to each other to "gauge" how accurate they are. They aren't. They just aren't accurate. If you want a more accurate hygrometer, spend $1000 and instead of reading "60%" as 56%-64%, you'll be able to read it as 58%-62%. Calibration does not guarantee accuracy, either, as these calibration devices themselves, too, have trouble with humidity measurements. There is a lot of literature on humidity and trying to find better ways to measure it and account for all of the variables.

That all being said, for our purposes, it is good enough, but don't fool yourself thinking that a 65% reading is really 65%. It should be read as 50%-75%, most likely 50%-65%.Although, some humidors are much better at measuring the upper regions, such as an oakton 357 for all those who store cigars and need them kept at say 65% (This oakton model does quite well and if it reads 65%, you can limit that at 60%-70% instead of 50%-75% like other, smaller humidors such as caliber 3).

Like a good scholar, I will put out some sources for anyone to read about the issues with measuring humidity if asked

TLDR: Reading a humidity number should not be read as a number, but rather as a range of values based off of that number and (honestly) the price of the instrument. Tools that give you slower readouts are better as they are not disturbed by your presence as much (body heat, skin moisture, breath, etc.).

Yea, most hygrometers are not accurate, thats a common issues, but it's better to have one that shows probably 5% too high numbers as to have none. Correct humidity it very important if you try to max out your yields.

The chart belows shows how the VPD change with different ambient/leaf temps. The optimal humidity range is pretty small, especially with higher temps and leaf temps with LED's are different to leaf temps under HPS/MH, because LED have almost no IR radiation.

With HPS you get the desired leaf temps of 27-28°C with ~25°C ambient, with white LED's you need ~30°C ambient to get the desired leaf temps. With 25°C ambient 50% humidity is enough, but at 30°C you already need ~60%.

This is one of the main differences with LED's and HPS growers switching to LEDs must take this into account and adjust their environmental conditions accordingly.

Darr26 said:

I've actually been trying this but it doesn't seem to bring the humidity up to much. I have also tried a couple cups of water

Click to expand...

How about one of these???
Mini evaporative cooler

Tejashidrow said:

How about one of these???
Mini evaporative cooler

View attachment 4160525

Click to expand...

Did I just see that on a tv ad earlier?
39.99
Lol

That cooler looks nice I may try it! And yes you most likely did lol when I looked it up it says as advertised on tv.

Humidity is naturally low where I live (High desert) so I'll most likely need a humidifier. Also the way I'm keeping the tent cool now is with a 18 in fan blowing through the vent side of my tent, and then a smaller 8 inch fan on top blowing out. I know not a great setup, I still need to invest in actual inline fans with controllers and a humidifier. Learning as I go lol there is alot to learn

Darr26 said:

That cooler looks nice I may try it! And yes you most likely did lol when I looked it up it says as advertised on tv.

Humidity is naturally low where I live (High desert) so I'll most likely need a humidifier. Also the way I'm keeping the tent cool now is with a 18 in fan blowing through the vent side of my tent, and then a smaller 8 inch fan on top blowing out. I know not a great setup, I still need to invest in actual inline fans with controllers and a humidifier. Learning as I go lol there is alot to learn

Click to expand...

Nice! My fiance is from there, too! Im from central valley so I understand the dry issue too

Need some help switched from 120 to 240 and my light controller has sideways outlet prongs. I'm told the light cord can be used with either 120 or 240 but the prongs are horizontal. What do I need to plug it in?

Tejashidrow said:

How about one of these???
Mini evaporative cooler

View attachment 4160525

Click to expand...

Lol! Forget it! It's crap!
There is a small 1,5w PC fan inside connected to an USB 5v driver and a little 4x 4" sponge! 2,5w at the wall, 12,50$ at e3ay!
Forget the claims in the TV, there are much better ways to waste your money!
A 10 pack sponges is 1$, you could make them wet and place them directly in front off your box fan and you would get 10 times more humidity, lol!

ThaMagnifice14340098 said:

Need some help switched from 120 to 240 and my light controller has sideways outlet prongs. I'm told the light cord can be used with either 120 or 240 but the prongs are horizontal. What do I need to plug it in?

Click to expand...

You need another wall plug! E3ay, am4zon, elsewhere online, walmart, literally available everywhere. Cut the old one off and take it to the next Walmart, there you go in the electrical area and ask for a matching plug. You can also replace the two wall sockets, if you believe you can do it! But it would be harder to find one siutable, because it looks like a twin socket, secured with a screw in the center.

Basically, the 1m2 plants release enough water into the air to keep a 5m2 room moist enough. Close all windows and doors in the room and open them only once a day! (at night, when humidity is higher or early in the morning)
You could set up a few yeast / sugar bottles* to increase the CO² content in the air, so you do not need to open the windows anymore. The humidity would rise quickly and you could do it without a humidifier again. Later, you can invest a gas system where the CO2 comes directly from gas cylinders. For sure cheaper like a humidifier and it has an immediate effect on your yield when you hold a level of 1000-1200ppm.

* 1-2gal bucket, 90% filled with handwarm water, 200-300g sugar, 7g yeast(1 bag), At first mix sugar and water, then mix 3tbs sugar water and 1 bag yeast untill its completely disolved, insert it into the bottle and mix it up.
In the lid you drill a hole for a small diameter hose, the other end of the hose you clamp behind the box fan.
Finished!
1gal of water and 200g of sugar last for about a week to 10 days(depending on brew temps). The first 5 days they produce a lot of CO2 (~ 900ppm / 1m2 tent) the last few days it decrease to 0. I run mine 8-10 days and put a second one in after 4-5 days, that means, I fill a new bottle every 4-5 days. This way I can hold a level of ~600-1000ppm and can keep the windows closed during the dry season with only two bottles. For eight weeks I need only 4kg sugar and 120g yeast. Brew and champagner yeast is available on am4zon in bigger bags (1oz to 1lb), baking yeast would be cheaper and you get it literally everywhere.

PS. Brew yeast lasts a bit longer than baking yeast, the latter dies earlier because of the alcohol content, brew or champagner yeast can withstand up to 25 volume percent. That means you can use more sugar with brew yeast.