Cannabis Grow Lighting Myths and FAQs with Dr. Bruce Bugbee

Dr. Bruce Bugbee debunks myths and answers FAQs on grow lights for cannabis based on his research so far at Utah State University's Crop Physiology Lab (see time-stamps below to navigate topics) and the next video in the series here: • Maximizing Cannabis Yi... . Bruce is a world-renowned crop physiology professor famous for his work in controlled environment agriculture for NASA and is president of Apogee Instruments, a developer of research-grade instruments used in precision agriculture. Bruce's lab at Utah State is one of the few with a license to study cannabis cultivation with several active research projects underway (see: www.usu.edu/today/?id=58336 ). The lab's license is to research hemp, but these principles apply to marijuana, including sativa and indica. Some of Bruce's answers in this video are based on what the research is showing so far, but further tests are underway. As this is a very hot topic right now, we will do our best to monitor questions posted in the comments below and ask Bruce to answer them in future videos.
VIDEO CONTENT
0:00 Intro
2:24 Light as one of the nine cardinal parameters
4:04 Can too much light cause problems with my cannabis plants?
5:30 How far should my lights be above my cannabis plants?
9:30 What is the optimum light intensity for growing cannabis?
16:59 PAR and PPFD explained
19:30 The best DLI (Daily Light Integral) for Cannabis
24:25 The proper tools to measure light levels
26:40 DLI levels for seedlings/cuttings
27:20 Photo periods and light pollution thresholds during dark periods
30:20 New light pollution sensors
31:30 Light requirements of different cultivars
32:50 Light quality effect on the synthesis of cannabinoids and terpenes
34:17 UV and Far-red effects on cannabis
39:40 Optimal spectrum for veg and flowering
42:52 Design Light Consortium (DLC) and light efficiency listings
------
Follow us to see all the cool places our sensors are used, get notices for free classes and how to videos, and product announcements!
-Blog
www.apogeeinstruments.com/apo...
-Facebook
/ apogeeinstruments
-Twitter
/ apogeeinst
-LinkedIn
/ 1084851
-Instagram
/ apogee_instruments
------
APOGEE PPFD HANDHELD METER VERSION
www.apogeeinstruments.com/mq-...
APOGEE USB SMART SENSOR VERSION
www.apogeeinstruments.com/sq-...
BUY AN APOGEE QUANTUM (PAR) SENSOR
www.apogeeinstruments.com/qua...
BUY AN APOGEE PAR-FAR AND RED - FAR-RED SENSORS
www.apogeeinstruments.com/red...
BUY AN APOGEE µCACHE BLUETOOTH MICROLOGGER
www.apogeeinstruments.com/mic...
------
LEARN MORE ABOUT DR. BRUCE BUGBEE
en.wikipedia.org/wiki/Bruce_B...
psc.usu.edu/directory/faculty...
------
LINK
Design Light Consortium: www.designlights.org/

[@sumthinfresh]

Finally, a grow video that doesn't start with " heyyy whaaaaats uuuuupp yooooo tuuube!"

[@sootrattlerolloff-road1415]

No doubt...and no annoying music droning in the background. Original ideas are sparse, and the ones that exist have been "Cloned" to the point of shutting off my sound and using close captioning, when/where possible.

[@fakename7570]

And...he didn't point to the bottom of the screen and mumble something about "...down below."

[@jamesmoisson]

DUDE!

[@yarbles_]

Somehow I'm writing this comment without being told I can leave a comment.

[@jamiepastman5594]

AMEN!!

[@bedward320]

When the student is ready the Master appears.

[@BRich-do1zk]

Lowkey needed this lol Preciate u🤙🏿

[@horaceguidry1541]

Sounds like Wisdom to me 🤔

[@tahu7454]

🤣🤣🤣

[@noplanb1266]

Aaamen...!!!

[@tswnotebook]

When the student is really ready the master disappears

[@Student-gr1sq]

I never thought I'd pay this much attention in school. Well played.

[@hypelogo2880]

Finally, someone that knows wtf they're talking about. Thank you.

[@kreature7946]

The weed that this guy grows makes you permanently high.

[@jamminjim1208]

LoL, that cracked me up.

[@lalahartwell1234]

Lol

[@wolfpac1970]

I would be ok with that.

[@Patrick-gf5xg]

Sounds like what I've been searching for.

[@jjohnmac1134]

you just open the box and you get high through osmosis

[@mandelaeffected2781]

When somebody has a doctorate and looks like my stepfather starts talking about cannabis I open my ears and shut up and pay attention!

[@joesquatch]

Mandela Effected You got that shit right

[@michaelbassett8076]

lol that is exactly what I was thinking when this video popped up and why I clicked on it

[@terryzweig2093]

What you said!

[@kwilsonjr]

lol! my thoughts exactly when I fired it up. "oh shit, this guy knows something. I better pay attention"

[@jammingj8187]

he absolutely knows his s***

[@kxspy29]

Wow, Dr. Bugbee motivated me to study something in my life after being lack of motivation for years. Thank you so much. I loved the video.

[@mart7379]

Sure would appreciate seeing all the other 8 of the 9 cardinal element modules, specifically for this plant. Thanks for all your work Bruce.

[@gueto70]

Maximizing Cannabis Yields with Dr Bruce Bugbee He has covered it in several videos but the titles are not always clear on the topic.

[@ReallyTY4Real]

Sir it was a honor to get this lesson from you, thanks for your contribution of actually GOOD information on youtube.

[@devjyarn]

I'll be the first to say yes please to talks on the other 8 parameters in regards to cannabis! Thanks for putting out such useful information.

[@nivshitrit248]

Me too! right after I finished this one I went looking for the 8 part breakdown and was disappointed when I saw this was uploaded 2 days ago

[@aetherflow]

Looking forward to the rest of this series! Very informative

[@ReallyTY4Real]

Me too, i am disapointed that he has all this knowledge and only now are we having the oportunity to have acess to it, at the same time im greatfull he is sharing it with us, the classroom/community is waiting for the next vid sir!

[@C...G...]

i'll second that! :-)

[@pseudonayme7717]

"When you see this once, you'll never forget it!" This guy obviously doesn't know me very well, does he 😁

[@lucasberard]

Thanks for this. I really like to see things broken down into their separate, quantified components. It lends clarity. I'm no stoner, I've battled PTSD for years, with limited results. I finally decided to try Cannabis, after getting a medicinal license. I have not slept so good in over a decade. It seems to eliminate my dreams, which I have had ONE good one in 15 years. I now intend to grow it along side our Hibiscus and Sugar Cane. I love the science behind it. Great job. Thanks again.

[@ExquisiteTouch.M.M.P]

Uh your not a stoner? 😂 😂 There is a band called sevendust and they have a song called " denial ". 😂 Ya ought to check it out. You my friend are a stoner wether you want to admit to it or not.

[@benwinter2420]

Not dreaming is not a good sign , REM sleep releases the human growth hormone that repairs damage

[@ExquisiteTouch.M.M.P]

@@davebryant8050 I'm not sorry but I do got to ask was you talking to yourself and then just happen to click onto my name by accident ? Where and what do you think you or your comment is even relevant to which comment if mine ? But you did happen to get one thing right, I do stay the f away from most people these days cause most of ya have your head so far up your own stinky asses that the stench is clogging your brains ability to transmit signals to your brains receptors any longer . A bunch of idiots wasting their god given brains thinking that the war on drugs is somehow a good idea for anyone other than those involved and whom profit from big prison business. For the rest of us in society it's a major drag . Then to say thc will never be accepted upon the masses? 😂 You must be in one of the slower to legalize states . 😂 You do realize that the legal so called better for you drugs kill and damage more people than all the illegal substances combined right? Tobacco and alcohol are by far more worse than especially THC/marijuana but can even be nastier than even heroin ! You foolish blind thing that let's other people use the brain that God gave you. Brainwashed idiot! You will find that there is a whole better world awaiting you to wake the f up over here . I would say a world with greener grass but I fortunately there is allot of work needed cause of all the braindead idiots like yourself has blocked the subs rays from lying dead asleep on the grasses . So wake up , get up , breathe on your own , and for God sake think on your own . Your God is shaking his head wondering why he gave people like you brains if your just gonna let others use it for you ! . F-ing dumbass

[@Shawn-pk4hc]

@@benwinter2420 Its great when the alternative is terror and years of sleep deprivation!

[@benayers8622]

Ikr!! 🤣🤣🤯@@ExquisiteTouch.M.M.P

[@ALEXZANDERMEJ]

Chuck Norris only smokes the weed this guy grows

[@shawnewaltonify]

Dr. Bugbee going above and beyond selling instruments in this service to community. Thank-you for explaining this, it is critical that we know it, and you care that we do.

[@chipfriday9967]

Dr. Bugbee may be getting a little something out of this. Please, I don't begrudge him in the least for making an honest buck on the backside.

[@michaelsegal1586]

He's selling ePar meters now and in a few years he'll change his mind re: UVB and Apogee will offer meters that measure the full range of Photobiologically Active Radiation (PbAR). 780nm is the lowest frequency of PbAR and 280 nm is the highest frequency.(The definition is that PbAR is the bands of frequencies that trigger and/or energize beneficial photo/phytochemical reactions.)

[@harebear420]

@@chipfriday9967 i❤ooloollo

[@harebear420]

❤oo

[@BigLonerG]

*Pauses* _ "Cannabis looks something like this" _ *Draws curve with affection and clearly shits on the lettuce curve* _ Tells us to "Look at this curve, look at that curve." twice _ Proceeds to a wholesome "Woow" _ Ends it all with "This is cannabis" _ *Writes it down with intent to kill* Hahaha these are awesome lectures! Thank you for sharing some knowledge in such an accessible way!

[@rickw7903]

No doubt. These videos actually keep me captivated and are truly food for thought.

[@AbelbenAdam]

Because it's a lie. I was pulling 500g/m2 with ppfd 200 max. Now I'm at 800 and there's about 15% difference. The whole lecture was about waste of money.

[@bremlquan]

@@AbelbenAdam any difference in quality?

[@sithlordteleportdinero5166]

@@rickw7903 Perhaps so but you will still fall

[@lrconroy790]

Thank you Sir. To find a lesson from a man of your credentials is indeed a treat! Your knowledge is invaluable to me.

[@thedudegrowzzz]

Im gonna buy a mexican candle and put this mans picture on it. God bless

[@WayGroovy]

So far this has been my favorite video related to cannabis growing. Thank you for the knowledge!

[@BrendonLeaman]

I've been growing for 10 years and the minute this video started playing I was watching the screen like a kid sitting in the front row.

[@umdasu]

question is did it change your grow?

[@BoleDaPole]

Nah he still growin mids 😶😐🙂🙃😆🤣😅 Lol jp idk wtf he

[@kristinabelushi9911]

Thank you for putting collegiate level information out into open source availability for easy access. I am ever so grateful for your up to date information.

[@whyguy3651]

Revolutionizing how people see light and growing. Just in the past 3-4 years we’ve seen leaps and bounds in lighting technology and our understanding of it. Thank you for all the useful information!

[@Jclarine]

Great information, I would love to see a series on the individual environmental factors affecting growth for Cannabis. Thanks Dr. Bugbee, I miss being in the Crop Physiology Lab with our class. I've gladly paid thousands of dollars to Utah State for information this valuable, it's amazing to see it made free to the public. -Joe

[@calmchess2515]

Thanks Doc ....give him a pay raise I wasn't confused during his lecture at all.

[@davidsoumol4423]

I never thought of so many fundamentals for this piece for a good production. Really the study and maximum information is essential. Thanks.

[@MarkecJeJ]

Thank you for the best video KZbin has to offer on this topic! Your students are lucky to have you as a professor!

[@420edu7]

Thank you for sharing your knowledge, we can learn in a week what took a lifetime to study

[@moej.priest6861]

well said

[@dannyschumaker]

? a week what you got dial up or something lol it only takes 44.11 mins

[@pliit2101]

He said it took one year to study lmao noob

[@papacos4745]

Great Teacher. His teaching style is easy to understand and his explanation for different situations of growing was very interesting. Thank you again for your hard work & research on this topic. I learned a lot on this episode. Happy Growing ✌️🌎

[@Voidwalker093]

This guy is such an effective teacher! Been trying to learn about this but I haven't found anything as in depth as this video. Worth watching till the end even if you already have the knowledge.

[@sloppyglizzy8313]

He has several others on here so if you liked this watch the other content too!

[@seanludeman4940]

He really is a fantastic teacher

[@user-jf4cf9sn7d]

​@@seanludeman4940Но есть и у него спорные вещи)))) Хотя послушать никому лишним не будет. Непогрешимых нет. Тот же Хорхе Сервантес, хоть для кого то икона непогрешимая. Но ошибался и он.

[@MrKrzys01]

I've watched this video about 5 times and intend to do so again. Absolutely invaluable education.

[@rumplestiltskin3814]

Love the video, I'll be watching all I can find. 👍👍 Great breakdown and delivery of the info.

[@wianvonschmidt]

This video was true pleasure. Thank you, more knowledge here than 10 hours of self study 🔥🇿🇦

[@hartfordboothe7466]

Thank you for taking the time and effort to make and post this video. This is clearly presented and has useful information, it is appreciated.

[@RaulTorres-lj3ki]

This is simply amazing how one can use science to get the best yeld possible. There's a lot of misinformation about cannabis growing and this guy just made it so easy to understand that I feel like spreading this information in my country! Thank u so much!

[@tuffsensi1196]

Thank you for sharing your experience and knowledge. It is appreciated

[@LostInAce]

Brilliant and thorough at a steady jogging pace. I could listen to Dr. Bruce Bugbee all week! Thank you.

[@allxdup1909]

This is the ultimate lecturer, someone who knows what he is delivering and is passionate about it. I could listen intently for hours, I just caught myself leaning into the monitor haha. This awesome content is right up my ally, thanks so much Bruce.

[@ldubel5922]

Thank you for the effort you give. Knowing and understanding root cause and effect driving growth is critical in my opinion. This explanation video is exactly what I was hoping to find and learn. :)

[@dukedaman5671]

This makes me feel like I'm back in 🏫... This time I just don't want the bell to ring no time soon.great teachings sir...

[@justme-ud2vk]

Youre amazing, Sir! Im so grateful for these explanations. Thank you for a clearer perspective!

[@pineapplehazeclub]

Hi, I am a gardener in my small farm at Lanzarote, for two or three years now and I really appreciate your work, Doctor, very valuable information. Thank you very much and good luck to all

[@mehmedmehmetova6321]

i appreciate that Dr. Bruce had a great research and share with us. Thanks for sharing your knowledge !

[@Gah_Hofs]

everything as clear as water, amazing lesson, amazing teacher!!

[@dazoosocialworker]

I need this man's whole lesson on cannabis. This guy is amazing at explaining this.

[@tthtonekid]

He does a class every year for intermediate to expert frowers

[@bigskyproducers]

Wow one of the best lectures I've had that I didn't have to pay for. Truly incredible!

[@DanielBowens]

After watching all of his videos I feel like I should be getting some kind of certificate or degree in the mail 😂

[@sammylove14]

I know I feel like I’m in class, wearing my glasses and writing down notes.

[@LynnaeaEmber]

Maybe a certificate but certainly not a degree.

[@digitalgods5568]

Your certificate will be printed on Hemp paper.

[@justinbrew483]

Indeed

[@charlestonbrown3383]

What's your addy!??

[@TurtleGlow]

Like many of the other commentators, I also would love to see this made into a series of video seminars on plant physiology led by Dr. Bugbee. Since dialing in those parameters increases the amount of light these plants can use, and it would only build more renown and good will towards the Apogee brand, I would make the argument that developing this into a series would increase revenues for your company. Might we expect further videos along these lines? Glad to have the very informative video description. Not many channels use that section to full effect.

[@alexdavis7069]

I've got to say, usually you go to the comment section of youtube and it's full of bad takes and negative comments, but when it comes to the educational grass videos, you get the best comment sections. I think that says something about the usefulness of this plant.

[@markbertolet1985]

Thank You Dr. Bugbee for this exceptional lecture.

[@jakubhryniewicz5321]

Best 44 min advert I have ever seen! Thank you Apogee of valuing your future customers time. Thank you Prof. Bugbee! ...Love your last name : )

[@chestrockwell3491]

I like hearing a logical dissertation of lighting. Too many stoners disseminating bogus half baked info.

[@shutin4good227]

You are an amazing teacher mr.bee.

[@cincorodriguez7487]

Been saying this for years, now i can show people. Thank you

[@lukasstrydom6030]

Ah man this was a treat to watch! Thank you for sharing this pot full of golden knowledge!

[@glockasauruswrex6362]

Wow...excellent breakdown of light and photosynthesis!! Thnx for clarifying so much...as a noob grower, sorting through the clutter of info is key. This really helps...subbed

[@kobalt77]

This is amazing, thank you.

[@user-yq6fb3bc8u]

Always as professional as always sir; thanks for the stellar knowledge on cannabis and lighting.

[@JandBinMaine]

This was a fantastic video just started a grow room. I used to be a a chemist in a different life. Absolutely loved it!

[@golf-freq]

Excellent lecture! I learned so much -- you have an astounding talent as an educator. Thank you!

[@twokois7032]

17:46 He Knows What He Talking About.

[@HrDoktorBillerbeck]

Finally someone who presents the basics right.

[@sirsteadyeddie3478]

WOW! THANK YOU FOR THIS VID! SUCH AN AMAZING LECTURE

[@user-ot4ch4qh9c]

Thank you for posting this information freely and without bias

[@goodgreen4616]

Good job. Lots of info easily explained. Alot needs to watch these 👍

[@adriansaninja]

thank you everyone who made this possible!

[@nigelbrown5909]

Brilliant. No pun intended 😁 The single most informative lecture on lighting re cannabis that I’ve seen. Thanks Doc👍

[@nevinkush9911]

Thank you sir for the most useful advice and all the hard work you’ve done for us

[@matthewsgauge]

Thank you. I downloaded a light meter app and checked my plants. I just finished raised and now all the same. 12" makes a difference.

[@dogfaceponysoldiers5038]

I watched this video first then I binged watch ten others. Very good content sir! Throw atmospheric pressures in to the equation if you really love all this stuff! 👍

[@landofahhs_1]

Thank you, for sharing your knowledge of the components of cannabis light and growth requirements AND the explanation of the terms and units used.

[@Latsch82]

Dr. Bugbee is such a nice person to listen to. Thx for the great video! Very informative!

[@eric8630]

This guy is my hero... He explains everything so well.. so much detail and has created the tool we ALL need... WE ALLLLL NEED.. because "12 inches from that canopy" (especially at 100% power) is just ridiculous.. and this guy has helped me save many plants from getting too many photons and burning away terps.. thanks Bruce Bugbee! Seriously, could have explaied any of this stuff any better.. i still come back to this video regularly to try and get all this stuff in. So important and useful

[@michaelschneider9305]

It’s a great resource of knowledge that’s forsure

[@concreter6832]

if your vpd is all spot on u can have lights at 10 to 12 inches away at 100%towards end of grow ,i use 2 x spiderfarmer 7000 1460 watts all up get no burning just very healthy plants with large yield

[@benayers8622]

ikr i made this mistake when i switched from hps! My last run were bout 5ft+ but under the led lookin at 2ft max on a lone plant the rest are like 18 inches from bottom node to crown! Still managed to get them nice and dense but iv never ever seen a plant refuse to stretch like that b4! Thinking i might veg with them about 3ft 4ft away next time in the hope they stretch normally again lol never seen plants so short and dense ther like solid balls i mainlined topped and fimmed them several times though too so getting countless tops, i dont use a net but its kinda sog/scrog style just all verticals and budsites spread over the whole available area :) teach me to trust the internet in this day n age lol! Also tried n auto cos i was in a rush last time on internet advice they are "faster" 8weeks they said! Well thats BS too took 12 or 14! Was woody stemmed and rubbish even tho i did the recommended single tie down method and i coulda finished a normal one faster ffs! Wud hav been 10x nicer then too lol bloody advise everywhere is tellin amateurs to buy autos cos ther easier! Biggest lie ever way easier to set a timer!

[@JordanHilliard-vq1xb]

​@@benayers8622ya know I'm coming to the belief that autos are not as good and never will be as good as reg seeds.. even fem seeds have a range of potential problems and require extensive breeding to find stable genetics that won't herm under various stressors.

[@DRSHANKER]

I'm going to a college for some vocational skills. And just watching this video makes me miss having a GOOD TEACHER

[@nickdurrant4283]

thank you so much for explaining this in a scientific and objective manner, it was extremely illuminating.

[@raidnoob124]

Well thanks, KZbin for suggesting me this video and congratulations on the quality of the content.

[@samanthaelizebeth1776]

Fascinating 🌱 agriculturally 💡

[@naptime_riot]

So well presented, so full of information, so good! Thank you Dr. Bruce!

[@Gnomestress]

This was a lovely lecture and I've learned a lot. Thanks for including the physics / math

[@hoggarththewisesmeagol8362]

I like how he doesn’t overcomplicate the subject whilst still getting his points across. I wish my science teachers at school had been like this. I think most of them just liked the sound of their own voice

[@muehahahaha]

"light quality does not have a huge effect on the ratio of cannabinoids" Very good video, amazing stuff

[@RowsOfGreen]

This is brilliant

[@thewidowed4743]

Finally I found you. Thank you guys for your time and effort to spent on researching cannabis plants and to share it with us here, finally I can see more in depth behind the grow. Thank you

[@Sportsmaster222]

Great info yall, we thank you for all the research!

[@johnnycobb00]

i dont even grow cannabis , im just watching this for the science lol

[@swad1513]

[@louche33]

Thanks for the information, can't wait to see what uv and fr do for maritomatoes

[@ReallyTY4Real]

Lmao, that maritomatoes reference tho lmfao

[@leeadickes7235]

UV will kill plant tissue in a few hours. Even just a 12w bulb. Works good to sterilize a reservoir If its submersible. Do not look at UV lights.

[@leeadickes7235]

Use CMH lighting and you will get all the UV needed.

[@sixmillionsilencedaccounts3517]

That's incorrect. UV-B output on CMH is laughable because UV-B is blocked by glass. It's about 1/10 of a sun which is not enough. You need UV-B (mercury) bulbs to get some real output.

[@mathershane8732]

What a great video so great gonna make my growing much easier ,thank u so very much i look forward to watching the rest from this channel :))

[@dank_c.152]

This is what most companies need to be studying if they are going to produce lights for any horticulture use. All I see online in descriptions is the par foot print. They don't really say anything about DLI and alot of the stuff you talk about. Great video thank you for taking the time to make these.

[@justint6619]

Download this before the lesson is gone this dude knows what he's talking about!

[@orion9k]

@Grow Tent Tomatoes how do I download it?

[@bootangy]

@@orion9k lol hes stoned

[@Duckinggreattime]

"Thats a pretty fat line" took the words right out of my mouth 😂

[@zacharygryn7959]

Where can I get some of these fat research lines

[@markross6818]

Very straightforward treatment of the light parameter. Thanks!

[@Tonytone969]

Thank you so much for this new ‘’light’’ on lighting .. very informative 🙏

[@MegaSandyvagina]

It's simple. Cannabis will only grow as fast as the limiting factor

[@syberspy9]

"That's a pretty fat line" - Bruce 17:50 All funny comments aside So glad someone is actually studying these topics for cannabis and sharing the knowledge! Looking forward to your next video on nutrients possibly?

[@_7l_810]

medicinal nose candy..

[@Stoneynchumley]

I was just watching and started laughing my ass off. I had to go check the comments before I finished the video. lol

[@leorickt.9604]

Note: you can use this information to grow any plant

[@jesserosas5452]

...bc at 17:20 you can see that smaller ones are more common

[@Turk1881]

Excellent video! Thanks for sharing the knowledge, sir.

[@ExquisiteTouch.M.M.P]

Thanks for listening he says. No thank you for a wealth of information presented in way that was both easy to pick up and kept us drawn in . 👍 Great job! Thank you!

[@express375]

Really interesting, and I understood some of it 😊, thanks.

[@mrdavinci4178]

Thank you for clearing up facts.

[@stickynickyt]

Thank you so much, Dr. Bruce!

[@damicolicious]

This is a great talk on this subject. Enjoyed, and recommended!

[@petertaylor8922]

Thanks for this ...lots of good information based in Science.

[@colinb1331]

Great video, thank you! I must say there is still much debate to be had on the issue of spectral impacts to cannabinoid content. I suspect FR:R ratios may play a larger role than overall "PAR" spectrum. I welcome the day we start quantifying based on total radiation biologically utilized in the plant. We need more educators to reach out through platforms like this... I can say my Apogee SP-420 is within arm's reach and has become one of the most useful tools even around the house. Absolutely essential in horticultural consulting to have a meter from Apogee or LiCor

[@michaelmcdermott3802]

brilliant teaching and delivery. good to see a normal human. Well done sir

[@___________________1]

Thank you for focusing on measurements, very informative and educational !