Maxsisun PB2000 Pro (light intensity question)

Hi all, newbie grower here working on my third grow with some GSC photoperiods. This is my first grow with these new lights in my 4x2x5 tent and also my first light with dimmers. I've used MH600 for my previous two and I thought they were OK for maybe one plant, but now I've been trying to grow 3 in 3 gallon pots for a SCROG.

I've had these lights (Maxsisun PB2000 Pro) on 50% from seed, and they seem to be responding well and growing fine. I've tried bringing it up to 60-70% recently and I've noticed what appeared to be light burn so I've brought it back down to 50% and they seem to be doing fine now.

Currently I have them hanging about 18" from canopy and am trying my best to keep the height wide and low as my tent is on the shorter side and I hope to flip to flower soon.

The lights at max power pull supposedly 200W from the wall, so currently I'm throwing roughly 100W to my girls in week 5 from seed. Should I be increasing power throughout grow? Am I not utilizing my light to the fullest? If they appear to be fine at 50%, should I expect to continue in veg and through flower at 50%?

I guess this is more of a general question since I figure if it seems to be working the way it is, why change it?

Thanks on advance and I appreciate any advice you all could provide. I recently started growing and I love it. It has become an obsession and I spend quite a bit of time nowadays lurking around here but I can't seem to find much information about these lights from people here.

I’m using those and love them got 3 of the 2000’s I keep mine on full blast but big room never grown in tent. You got photos? And for veg I would think your fine but go up when in flower my suggestion but I’m sure somebody will have other ideas

Here are my girls as of yesterday after some light-LST. Still learning so any advice and opinions relating to anything is welcome.

I've also a bit worried that heat will cause problems as I raise the intensity in the near future. Currently at 50% in this tent I get Temps around 77-83F and summer is just around the corner here in Socal. I don't have an exhaust fan installed yet but I think I may have to install that soon. Thinking also of running the lights during the nighttime hours when it's a bit cooler when I flip to flower.

Yea that’s where those tents screw you they look nice. These were mine before I flipped I just fimm mine they finished nice

Bsmoke78 said:

Yea that’s where those tents screw you they look nice. These were mine before I flipped I just fimm mine they finished nice

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Damn, those look nice! I will try FIM/topping next grow.

I love these lights for the price I got them for this past 4/20 sale. Got them for around $140 after a bunch of coupons.

Have you tried other lights? Do you find these tend to run hotter than others? I have one clip-on fan pointed right at the driver, and will have to see how the Temps change after an exhaust fan.

Kvdavesexyshad said:

Hi all, newbie grower here working on my third grow with some GSC photoperiods. This is my first grow with these new lights in my 4x2x5 tent and also my first light with dimmers. I've used MH600 for my previous two and I thought they were OK for maybe one plant, but now I've been trying to grow 3 in 3 gallon pots for a SCROG.

I've had these lights (Maxsisun PB2000 Pro) on 50% from seed, and they seem to be responding well and growing fine. I've tried bringing it up to 60-70% recently and I've noticed what appeared to be light burn so I've brought it back down to 50% and they seem to be doing fine now.

Currently I have them hanging about 18" from canopy and am trying my best to keep the height wide and low as my tent is on the shorter side and I hope to flip to flower soon.

The lights at max power pull supposedly 200W from the wall, so currently I'm throwing roughly 100W to my girls in week 5 from seed. Should I be increasing power throughout grow? Am I not utilizing my light to the fullest? If they appear to be fine at 50%, should I expect to continue in veg and through flower at 50%?

I guess this is more of a general question since I figure if it seems to be working the way it is, why change it?

Thanks on advance and I appreciate any advice you all could provide. I recently started growing and I love it. It has become an obsession and I spend quite a bit of time nowadays lurking around here but I can't seem to find much information about these lights from people here.

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I have that light but mine does not have a dimmer,so its on full blast all the time and mine doesnt have IR. My plants were growing 2 plus inches a day at 14' away from top colas. I would recommend keeping the light at 100 percent the entire time and just keep the light at 20 inches in the vegetative process and then in flowering switch it to 14-16 inches,i do 14. I currently have 6 plants 3 small elevated at the same height as 3 of my 5 foot plants and they are all prospering. I have them in 3 gallon fabric pots. I was looking for an upgrade and I purchased this ativa qh2000,it had better specs but only 434 led pieces compared to 700 on this maxisun but the diodes on my maxisun are lm251b and its a sosen driver instead of the 301b and meanwell, if anybody has the qh version lmk.

SkEE87 said:

I have that light but mine does not have a dimmer,so its on full blast all the time and mine doesnt have IR. My plants were growing 2 plus inches a day at 14' away from top colas. I would recommend keeping the light at 100 percent the entire time and just keep the light at 20 inches in the vegetative process and then in flowering switch it to 14-16 inches,i do 14. I currently have 6 plants 3 small elevated at the same height as 3 of my 5 foot plants and they are all prospering. I have them in 3 gallon fabric pots. I was looking for an upgrade and I purchased this ativa qh2000,it had better specs but only 434 led pieces compared to 700 on this maxisun but the diodes on my maxisun are lm251b and its a sosen driver instead of the 301b and meanwell, if anybody has the qh version lmk.

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Thanks for the recommendation, I will install an exhaust soon and try that out. Heat is my primary concern right now for the dimming. Currently at 70% power I'm getting Temps of up to 85F. The girls seem to be doing fine though, but maybe my yield will not be maximized without full power?

Kvdavesexyshad said:

Thanks for the recommendation, I will install an exhaust soon and try that out. Heat is my primary concern right now for the dimming. Currently at 70% power I'm getting Temps of up to 85F. The girls seem to be doing fine though, but maybe my yield will not be maximized without full power?

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Good call, raise to 20-24in...I deal with heat, live in the desert. I run my lights in flower from 6pm to 6am and keep the AC at 75 at night. During the day with the lights off, tents stay in the low 80s. Definitely get an exhaust fan asap....that will help control heat as well as at least 2-3 fans inside for circulation.

Dank Bongula said:

Good call, raise to 20-24in...I deal with heat, live in the desert. I run my lights in flower from 6pm to 6am and keep the AC at 75 at night. During the day with the lights off, tents stay in the low 80s. Definitely get an exhaust fan asap....that will help control heat as well as at least 2-3 fans inside for circulation.

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Yeah, thanks. I live in SoCal so it's starting to get pretty hot now. For my next grow I will have to plan on setting the light timer for "on" during the coolest parts of the day(night time)to help control temperatures. Probably better to do this anyways so I can water/feed/train when I'm back from work.

Will definitely need exhaust fans though.

Forgot to mention that I do also have a couple of clip on fans in there to have some circulation at least to prevent stagnant air. That's probably what's still keeping my girls alive right now.

For veg you just gotta deal with it, can get them on a night schedule as soon as you flip

Dank Bongula said:

For veg you just gotta deal with it, can get them on a night schedule as soon as you flip

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Yeah, that was my plan to change the hours of light during flip... but apparently my seeds that were supposed to be photoperiods are autos. I'm not sure if I want to change the light cycle now even though I understand that light cycle is not that critical for autos as they have a predetermined rate at which they finish. I don't want to induce any kind of stress at this point in the grow as they're about 6 weeks now.

Altering the light schedule to put your majority of hours during the evening will not stress your autos. Run em on 18/6 or 20/4. You can leave the light on for extra time until you get on track.

Are you sure they are not just showing sex and pre flowers? You are at 6 weeks roughly...so it is around that time. Might as well crank the light and flip 12/12 now.

I'm pretty sure these are straight up flowering now. I've attached a photo of the three (as of yesterday) I have growing in the tent. (Would also appreciate any other tips/advice for my plants and setup).

Thanks for the tip, I will start the process tonight to start transitioning the light period to the evenings.

SkEE87 said:

I have that light but mine does not have a dimmer,so its on full blast all the time and mine doesnt have IR. My plants were growing 2 plus inches a day at 14' away from top colas. I would recommend keeping the light at 100 percent the entire time and just keep the light at 20 inches in the vegetative process and then in flowering switch it to 14-16 inches,i do 14. I currently have 6 plants 3 small elevated at the same height as 3 of my 5 foot plants and they are all prospering. I have them in 3 gallon fabric pots. I was looking for an upgrade and I purchased this ativa qh2000,it had better specs but only 434 led pieces compared to 700 on this maxisun but the diodes on my maxisun are lm251b and its a sosen driver instead of the 301b and meanwell, if anybody has the qh version lmk.

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Right now I have 6 plants under a Maxisun pb2000 and a Ativia qh2000.. I have one up top looking down and i have one on a shelf facing the plants. As long as you have circulation,nothing blocking off the plants you should be fine. The only time i had mildew problems was my first grow,that white powder substance showed up a day after I blocked off my plants which caused a circulation problem.. I have a Lux meter that also has a temperature on it and directly under the light registered at 78 degrees,which is perfect.Without the AC unit the temp gets up to like 82 degrees but theres never a problem with the plants,only a comfort problem w/o AC. I have a commercial circle fan that i keep on medium facing the plants. If your grow space is larger I would add more fans. Make sure your plants are well pruned so more air circulates. Good luck with everything

Kvdavesexyshad said:

I'm pretty sure these are straight up flowering now. I've attached a photo of the three (as of yesterday) I have growing in the tent. (Would also appreciate any other tips/advice for my plants and setup).

Thanks for the tip, I will start the process tonight to start transitioning the light period to the evenings.

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Yes,your plants are in early flowering. I always use auto flowering bc it makes things less complicated when growing several plants at different stages. If its already in flowering and you did not switch-thats a little strange,I would imagine you flip the lights anyway but if its already in flowering mode im not really sure if it makes a difference.

Kvdavesexyshad said:

I'm pretty sure these are straight up flowering now. I've attached a photo of the three (as of yesterday) I have growing in the tent. (Would also appreciate any other tips/advice for my plants and setup).

Thanks for the tip, I will start the process tonight to start transitioning the light period to the evenings.

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I would imagine growing in a tent causes a lot of heat problems. I boxed off my plants in a make shift like tent and as soon as i did that mold appeared. It keeps appearing because if you dont catch it right away it spreads fast. The main problem that causes this is air circulation. Like the posts previously said you might very well need a vent but you can make sure your plants are on a lighting schedule that keeps the room the coolest.

Kvdavesexyshad said:

I'm pretty sure these are straight up flowering now. I've attached a photo of the three (as of yesterday) I have growing in the tent. (Would also appreciate any other tips/advice for my plants and setup).

Thanks for the tip, I will start the process tonight to start transitioning the light period to the evenings.

Click to expand...

Since they look like they’re autos leave the light on 24/7 auto apparently like 24hrs of light.

24 hours of light is what most people do for auto flowering plants but, its not absolutely necessary. I do 18 only bc i need to sleep&the plants r in my bedroom-lol The schedule I do is lights on 7am to 1am. I know a lot of people that have autos but run the lights at night time to take advantage of the cooler air as well.