LED Lights Causing Low Yield ?

[rydin4life]

I'm completed four grows using only autoflowering seeds, although my last batch was Mephisto's Ripley's OG that didn't flower so I had to force by going 12/12...anyway, on a few different auto strains I'm averaging about 1.5 to 1.75 ounces per plant. I'm growing in 3 gallon fabric pots, using Fox Farms Happy Frog and/or Nectar of the Gods #4 soil, and Botaincare Grow and Bloom nutrients. I just started using Bloombastic as a way to help increase bud density. I'm using a 4x4 tent with 4 MarsHydro 300W lights going 18/6 (except the current Ripley's OG that had to go 12/12). I water when plants are dry and go until I get a good amount of runoff. I do a good amount of LST and defoliate the lower fan leaves. My humidity and temps are admittedly higher than they should be despite using all available open air vents on the bottom of the tent, an oscillating fan for circulation, and a 4" exhaust fan with carbon filter.

I feel that the yield is a little light so I'm wondering if those MarsHydro lights should be replaced with a better LED? Thoughts?

[DrPhoton]

I have never been a big advocator of the cheaper fixtures on the market. The mars fixtures are what they are, cheap. Cost mostly dictates the potential of how efficienct a fixture can be made. The cheaper the fixture, the lower its efficiency will likely be. Fixtures that have efficiency levels as good as sodium discharge, typically cost around $1000 or more.

Mars claim their 300w units are equivalent to 150w, but typically manufacturers over rate their products as there is no standard of conversion.

User reports suggest that they are more likely closer to 100W HPS. With an average 3-4 ounces per light. With 4 lights typically yielding around 12-14 ounces max.

Check my articles out if you havnt.

[DoctorJohnson]

I'm using a 4x4 tent with 4 MarsHydro 300W lights

So 150 watts of LED light over each four square feet. That's adequate but nothing like optimal. More light!

[Redwasp]

Yeah more light. Never tried those lights. But it must be hot in your area if you have heat issues. You said 4x4 area? And you have a vent fan already? Get a good hps in the 600 range and you will see a whole lot more. (I only say this because they are cheap)

It can be done with LED's. It can be done with cheap leds. But it all boils down to actual watts pulled from the wall. With cheap leds i use more watts than you do in a 2x4 area.

[Weed Pharma]

Without knowing how many plants you grow at a time, it's impossible to determine anything about the grow lights!

There are many factors which go into a good yield and lights are just one.
Your growing environment is the most important factor along and growers ability.

I use Mars hydro @ 240w - 1020w which yeild 3+ ounces a plant (auto) in 5 gallon cotainers in a 2x4x6 tent over 9=10 weeks timeframe.
This equates to 1 ounce a week at an electric cost around $1/gram with minimal effort.

I saw a noticable increase in yield when I upgraded my exhaust ventilation from 100cfm to 200cfm and started using 5 gallon nursery containers.

[Redwasp]

Lol never even thought of that. I was just assuming he filled the area. But yes what he said. If you dont fill the tent what i said is wrong. Sorry should have asked more questions.

[rydin4life]

I had four plants last time, so each under their own light..will do five plants next round. Should u add a fifth light in the middle of the four Mars hydro at this point?

[Redwasp]

Fill the tent or area with plants. Have light to cover the whole area. Never used those lights so dont know their coverage.

[Weed Pharma]

rydin4life, you may want to consider re-arranging the lights and height to make best use of overlap and total lights.
A quick estimate, from my experience with Marshydro's is your yield could be a around 11ounces a grow, with good ventilation, and quality seeds-
see this grow as example: https://forum.growweedeasy.com/forum...ies-autoflower
and the last post for light arrangement idea's. https://forum.growweedeasy.com/forum...-kiss-dry-cure

[rydin4life]

The tent is definitely covered with light..just not sure if those are powerful enough..wondering if I should..

1) Add a fifth light 8n the middle of the tent for more light intensity..possibly a Viparspectre 450 LED

2) Replace the current lights with better quality LEDs of similar wattage.

3) Replace the four lights with two Viparspectre 450 LED reflector's

4) Install a 600w HID/HPS system. I currently have a 4" exhaust fan but I would need to add a 6" fan for the light cooling with a separate exhaust outlet just for the light, correct?

I have a tough time keeping the tent cool now so Im not sure that using a HPS would be the way to go...but open to suggestions

[Potted]

Get a adjustable ballast on your 600watt HPS and a 6inch adjustable exaust fan I’m currently using a 440 and between the two am able to keep temp’s within range. Lol

[Inuart88]

Check out my grow journal. I just upgraded to leds last month. I waited a year the Technology i feel was not worth using them till just recently. I use AGROLED sun Bloom and Veg. The agroled doesn't tote the claim this 100watt light = 7800watt of hid bs. They state on the box 274watt 414ppf so they know there shit. I feel any of those amazon Chinese lights are shit. This is a personal opinion.

[Redwasp]

Your yields per plant arent bad. Could be alot more but up to you. Hard to say what you should do. Could be something other than a light issue although unless your running 1000 watts in a 4x4 more light would increase the yield.

[rydin4life]

If I go with a 600w hps that has a 6" fan, do I still need a separate vent fan with filter or is the fan in the light good enough? Also, do I put the filter on the light cooling fan too?

[Redwasp]

Well in my 4x4 i have 3 fans. 2 above one below. A 6 inch exaust. And a carbon filter on the exaust (unless growing a non aromatic plant you need a carbon filter even if where legal.)

[Redwasp]

I Use 2 viperspectrum 450s per 2x4 area. Don't get rid of what you have. Like i said your yields arent bad. But you asked how to increase your yields and more light is usually needed. The more light you have the denser the buds and the bigger they get until light saturation. Ive been slowly testing what that amount is but yave not found it yet. Lol

[rydin4life]

My current fan is a 4in rated at 190 CFM. I could upgrade to a different 4 inch at 200 CFM but that doesn't seem worthwhile.

I have a total of 528 watts of light for 16 square feet which is only 33 watts per square foot. Going for 50 to 100 watts per square foot would put me at 800 to 1600 Watts. It sounds like I should upgrade the LEDs 24 lights pulling anywhere from 200 to 400 actual watts each...possibly four of the viper spectra 450 for a little over 800 watts. Would four of the viper spectra 600s be too much for this space?

[Redwasp]

And i Use 1000 actual watts for a 4x4 area. Ill send a pic of what that does to photo plants in a minute.

[rydin4life]

So don't necessarily replace the current lights, rather add a fifth light might be best..something like another 500 actual watts or so to bring the total to around 1000 actual watts? I guess I was thinking the Mars hydro lights shold go, but keeping those 528 actual watts with another light at around 450-500 actual watts is a good option.

[Weed Pharma]

No- don't replace the current lights- you will need to get things in balance- before any additional light will be additive!

Are your fabric pots fillled with roots by the 3-4 week of flower?
Are there any soil dead/dry spots at harvest?
Do you grow in the final pot from start to finish?
Have you run a grow @ 20/4 for autos?
Did you reduce the nutrient levels for auto's, LED lights and your grow size?
What do your temps run?
Are you getting pests?
Have you considered Si and Cal/mag?

[Redwasp]

[KingKush]

Amazing!

[Redwasp]

Thanks. Yesterday was exactly 4 weeks after starting flowering. Im guessing 4 to 6 weeks left. Not sure i have enough yoyos to hold them all up when they start to lean and fall. Guess ill get more. Think this will be my most productive yet. But only time and god knows the answer to that question.

[rydin4life]

I'll check rhe pots for roots as I have two more plants that harvest this weekend.
I do grow in the same pot from start to finish and have been on 18/6 cycles except for the recent 12/12 swith after this round of "autos" didn't flower.
no pests..and I smart with 1/4 dosage and work up to 3/4 dosage for grow and bloom nutes.
temp with full tent are in high 70s and humidity in high 60s. I moved a dehumidifier closet to the tent in my basement, have a 10" oscillation fan and the exhaust fan running on same schedule as lights. Bottom screened vents are also open for airflow.
I do use botanicare calmag, but not sure what you mean by si.....
thanks for all the input!

[Inuart88]

Run fans full time I have mine running 24/7 you are leaving stale none moving moist air in your tent your asking for trouble.