Diy CXB2530 grow

Ill start with a little introduction. Ive been growing since i was 14 years old so thats almost 8 years now. Ive got a decent amount of grows under my belt but unfortunately ive never been able to grow without restrictions due to living at home and having to keep things on the smaller side.

When i found out about cob leds and how efficient they are it was like a ray of sunshine on my dark day. No longer would i be stuck with 100 watt cfl grows and 50 gram harvests. I chose cxb2530s after much debate. My room is approximately 16.5 x 36 x 24, though it was originally only half as wide to begin. I decided it would be better to have multiple smaller cobs to spread the light evenly over the canopy and the price of the cxb2530s was much more agreeable.

I originally designed the room with the intention of doing a 100 watt diy smd micro grow. Then during my research i found out about cobs and scrapped the smd idea. By the time i had done my ppfd calculations and fully understood what ppfd was i had basically already ordered the parts. Discovering i had about 2-3x as much light as i needed for the space, i opted to increase the size of the grow room.

For parts im running
3x 3000k cxb2530 u2 bin
3x 4000k cxb 2530 u4 bin
Mounted with arctic silver thermal paste and molex cob holders on a 7.28x10 heatsink from heatsink usa
I used a meanwell hlg120h c500b

Im driving the cobs at 500ma for approx 51% efficiency. The cobs draw about 17 watts at that amperage and gives me about 102 watts in total. For cooling i have 2 3 inch pc fans and a semi ghetto rigged shroud repurposed from an old pc case.

I dont have my sheets handy but i remember calculating my ppfd to be somewhere around 1200.

Strain wise i ordered 6 seeds and so far 5 have popped out of the soil. The strains i have are
2x white castle from nirvana
2x strawberry sour diesel from devils harvest
2x canadian cheese freebies that have no info listed on the site

So far everyone but one of the strawberry sour diesel has popped out of the soil. Im keeping them under plastic bags for humidity right now so pics kinda suck.

My grow room is in a secondary building on my parents property and as such it isnt well insulated and i have to do the best i can to keep temperatures as close to acceptable. As such i run my lights at night because electricity is cheaper at night and it keeps the heat down. It got up to nearly 100 degrees in my room one day but for the most part i can keep it down to the 85-90 range which isnt exactly ideal but its the best i can do.

For nutes i have always stuck with botanicare. I used the pro grow and pro bloom formula for every grow ive ever done and since i could afford to this time around ive expanded and gotten some liquid karma, cal mag and humega from the organicare line. I also plan to use honey water for carbs and provided my compost is acceptable this year i will be brewing compost tea.

For soil i use black earth. Any black earth usually as i find its a good base. If i hadnt been injured in a car accident i would be buying worm castings and the like and mixing my own soil with the black earth base as i usually do but its hard enough this year for me to deal with the black earth bags alone.

I plan to employ a modified lst/mainline technique wherein i will top the plants once, possibly twice only i wont defoliate nearly as drastically as is done with mainlining. My goal is to create short plants and maximize the amount of buds. Mainlining usually takes a bit longer than lst and needs more height in the grow space for full effectiveness so hopefully i can find a good balance between the two.

I have time and space restrictions. This could he the game of thrones grow as winter is coming and with it, a cold too great for my plants to withstand so ive got till november at the latest which means im only going to veg for about 2-3 weeks.

With 24 inches of vertical space, about 6 inches going to pots/rootspace and 5 inches of vertical space taken up by my light, i have 13 inches of grow space. This is gonna be fun

keep up the good work & im sure you're gonna get questions on how you built your setup

horribleherk said:

keep up the good work & im sure you're gonna get questions on how you built your setup

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Thanks man, and if thats the case than i might as well do a little write up for that right now.

My setup was fairly similar to what growmau5 does. I just marked where i wanted the cobs to be and then marked the holes for the cob holders. I just drilled them out and used self tapping screws rather than tapping the holes. I also drilled a series of holes to run my wiring.

The aluminum piece i used for my shroud was originally a corner panel on a pc case. I fashioned a break using scrap wood and a vise to bend the aluminum into a suitable shape.

I fastend my fans to each other with caulk, i love using it for pc fans because it helps to insulate the fan and stop it from vibrating and making noise. I had to beef the fans up a little with some plastic pieces i had lying around just to give that extra mm or two so the fans would slide snugly into the shroud.

I notice many designs have the fan aimed at the heatsink so the air hits it from above and spreads out over the fins. I dont know everything about airflow and how this works but ive always been given to understand that air travels better when it has a clear path or channel and so ive opted to have my fans blow across my heatsink instead of at it which creates a channel through the shroud from one side to the next. It does seem, however, that the cobs in the side of the heatsink closest to the fan are a bit cooler than the ones farthest away. Given that its a distance of only 10 inches i cant imagine this temperature difference is drastic.

Also due to my height restrictions mounting the fan at the side gave me an extra inch or so of height which is crucial.
I debated for a while whether i wanted to have my fans push air over the heatsink of pull it through the channel between the heatsink and shroud. The shroud is perforated for airflow being that its repurposed from a pc case. This influenced my decision that it may be better to push air through the channel as the perforation may cause inconsistancies in the airflow if i were to pull air through.

Now all of the above speculation may be completely asinine given that im definitely not educated in fluid dynamics in the least.

I left my dimming leads open as i dont see any real need to dim my lights. I touched on how i bought the heatsink when my box was originally half as wide so unfortunately the footprint of my light drops off in intensity at the sides but its really only the outermost 5 inches so im really not concerned about that.

Im hanging my light using chain attached to s hooks that are no longer s hooks because apparently im incapable of measuring things properly so when i drilled the holes for the hooks i had to bend the shit out if them to get them through. I may change this thiugh because the chains currently take up about 2 inches above the fixture which is about 3 inches tall and every bit of height i can get is gonna be crucial.

In other news all 6 seedlings have breached the soil and are looking beautiful. One of the white castles has that awesome mutation where its only got one cotyledon. Its like the tiny little first leaf set is sticking its tongue out at me.

I havent had to water much in the 6 days theyve been in the soil even with temps occassionally reaching a scorching 100 degrees (adding another exhaust fan today to help with this, at worst its only for a few hours in the afternoon when my lights come on before the afternoon heat dies down)

Probably because ive been misting them once or twice a day. Nowhere near as much heat coming off my light as the 150w hps i used to run so my concerns about them drying up or getting baked before they even get a second leafset are lessening, still not ready to take the bag humidity domes off them though.

I bought some neem and rosemary oil and some dr bronners peppermint castille soap to mix up for a natural pest defense. I also sprinkled the soil with some diatomaceous earth today. I avoided doing this before the seedlings had all crested (not even the proper term but i love the idea of the seeds cresting the soil, thats some good imagery) because ive gotten a bit of it on my outdoor plants and it seems to dry out and kind of fuck up their leaves in the spots where it got on them.

Im also using yellow sticky traps so hopefully with all this i should be bug free. The building i grow in is essentially a shed. Its not insulated or anything but my cab is built inside of it so its better than growing in just a shed. I have a bit of a buffer between the outside world and my grow but not as much as a house.

For temperature control and airflow ive actually devised a modular system that lets me redirect my outtake and change my intake source. For examole right now the shed is always a few degrees hotter than the outside, probably 5 at least so to keep temps down my intake comes from outside directly (all filtered) and i exhaust outside as well. When temps begin to drop however i start exhausting inside the shed so the warm air from the grow lingers and helps keep my grow warmer. When temps really start to drop i have a t fitting on my intake from the outside so i can draw air from inside the shed, outside the shed or both simultaneously so i can keep my temperature acceptable into about mid november to early december at the latest.

So 3-4 months out of the year i cant grow at all because its too cold and the other 9 months im subject to constant temperature fluctuations. For this reason i mainly run my lights at night to help keeo the temperature more stable. Unfortunately this means sometimes its hotter for them when its supposed to be nighttime and sometimes its hotter in the day. Fortunately this year ill be flowering from early-mid august through till hopefully the end of october and as the outside temps drop it should get easier for me to keep things ideal instead of just acceptable.

Alright ive written so much i cant remember what i was talking about when i started. Got some good old canadian no name dank, it has this really great subdued fruity smell that kinda gives way to a dieselly cat piss type smell. Real great rambly, slightly energetic in the mind kind of high with a relaxing body load thats decent for pain but ive had better. Good all around smoke. Picks you up when you need it and puts you down when youre done

Oh yeah i totally forgot, ill post a pic and a bit of a how to later but i rigged up two different styles of diy carbon filter using mesh pencil holders and plastic speaker holes. The pencil holders slide over the speaker hole like a sleeve, theyre fairly light tight too once theyre filled with activated carbon.

Took the bags off them yesterday. Temps are still way too high, im seeing signs of heat stress and im not liking it. Even though its only 100 degrees in there for 4 hours of the day tops its still too much. However i added a third exhaust fan and its helping but not as much as i hoped. Im going to rig up an exhaust system for my light, i might even move the driver to the outside of my box but really it seems to be the cobs that are putting out the most heat.

I also do homebrewing, so i have quite a bit of equipment and it would cost me nothing to set up a couple gallon jugs. Ive got several varieties of yeast kicking around, im leaning towards vhamoagne or bread yeast. Brewing yeasts are selected for their flavour and alcohol production whereas a bread yeast you want high co2 production.

Bread yeast craps out at about 14% alcohol and champagne i can push to about 22%. Given my understanding of chemistry the yeast that can break down more sugar will produce more co2 over its lifetime than the yeast that wont. Even though bread yeast is a more gaseous fermenter you cant get something out of nothing. A set amount of sugar will produce a set amount of co2 and alcohol.

Now im by no means attempting to say that this will be a properly calibrated, optimal co2 level inducing endeavour. Im just saying that it wont hurt my grow, it should help me chip away at my temperature issue e however minimally and knowing this gives me a little more peace of mind. Of course im going to run the calculations just to see exactly how effective this will be.

Im a firm believer in net benefits or the parts equalling the whole. A sub optimal system should never be cast aside in pursuit of an optimal one while you are still in pursuit. Or more simply put, less than perfect can still be better than nothing.

Interestingly enough, one of my strawberry sour diesels came out of the soil (the last one to join us) and immediately its cotyledons turned brown and looked rotten. So naturally i pulled the plant right? Wrong. I really want to grow out this strain, paid a little more for some higher end genetics just because i want to see whats out there. I decided to leave no girl behind and deftly sterilized my scissors and snipped off the rotten cotyledons and spread the tiny inner growth.

I am nearly 99% certain it will die, if it does live it will be about a week behind the others, maybe more. I havent checked them today and i do not expect it to be alive lol but in the back of my head i really do think its gonna make it so we'll see.

What would you do in this situation? I considered three option, one being to just kill it, the second being to snip the cotyledons as i did and the third would be to re bury the seedling? Why rebury the seedling? Just a hunch really. I recall one members post here about burying a tomato plant that had been defoliated and the plant popping back out of the soil within a few days and that what made me consider this as an option.

As i suspected would happen the strawberry sour diesel seedling whos cotyledons i clipped shrivelled and died. The underdeveloped leafset that i spread apart, was probably too immature for the plant to rejuvenate itself. Oh well, thats life and 12 dollars iirc lol

In happier news at lights off today temps were around 80, only a few degrees higher than outside, lights on is getting up into the low 90's which is due in part to both my added exhaust fan and the lower outside temperatures we're having.

I bought a piece of aluminum ducting that i will be fitting to my light soon. It wont be perfect but it should redirect the majority of the heat my light is producing and move it outside the box. Im going to try to make this into a bit of a modular system as well so i can connect and disconnect the ducting as my temperature needs change.

Down to 5 seedlings now, 8 days since they were put into the soil. All look happy and healthy aside from a bit of heat stess. Wont be feeding them anything aside from a light bit of liquid karma and humega, but i probably wont do that until theyve started on their third leafset.

I like to grow by feel. By which i mean to say i make an effort to learn how to "listen" to what my plants are telling me based on how they look and feel. So for right now i know theres more than enough nutrients in the soil for my seedlings. Thats not to say that i wait until i see a deficiency or problems to act either.

Also this is the first grow where ive ever had more than just basic veg and bloom nutes so im trying to keep myself on a leash and not go crazy trying out products ive never used.

The diatomaceous earth is defintiely doing its job. Im finding insect carcasses covered in white powder much more than im finding living insects and so far none of these insects have been major pests, just a few ants and small beetles.

Ill be mixing my dr bronners peppermint soap, neem oil and rosemary oil concoction soon. Possibly going to do an application on my outdoor crop as well provided they still dont have any budsites developing which usually doesnt happen until the first or second week of august anyways.

Im also reconsidering topping them at all. Time is a factor and i have to allow 3 months for flowering just to be safe. Which means september, october and november. Im going to veg until mid august for sure, which is only 2 weeks away. I will low stress train them for sure.

A late october-early november finish would probably be the smartest thing to shoot for. Then comes the fun of drying them outdoors in the november cold. Ive done it once before with no problems. Very slow dry, very nerve wracking but made for some excellent smoke.

Seeing some very slow growth and im having a hard time figuring out why. Initially i thought it was my temperature but ive had that under control lately and its only about 4 hours of the day where the temperature exceeds 86 degrees.

Ive calculated that for the area im growing in i should be able to easily hit 1500ppfd. The issue now is that there seems to be some debate on what the ideal ppfd is. Ive seen everywhere from 750-2000 quoted as being ideal.

Now i have no light sensor, and no way of knowing exactly what ppfd i get at a given distance from my light.

I have it as close to the ceiling as i can get it which gives about 15 inches between the cobs and my seedlings. Im into the second week of veg almost and barely have my second leaf sets developing.

Going to do some troubleshooting today and try and figure out the problem. Maybe my grow box needs to be rebuilt a third time so i can back my lights off a bit more.

If anyone is reading and wants to chime in theyre welcome to do so. Ive never had growth this slow before and im doing everything the same way i usually do it. Something tells me its my cobs. Maybe ill just get a pot and dim the fixture till growth rate is acceptable.

Gonna be dissapointing if i cant utilise the full output of my light though.

Rebuilt the growbox, hopefully for the last time. Its now 3 feet wide, 3 feet high and 16 inches deep. Hopefully now that i can back my light off by another foot ill start seeing some proper growth instead of a bunch of stressed out little plants.

I fully set up the ducting for my light fixture and with the added room inside the box im hoping my temperatures will be alot more stable now.

I mixed up a litre of water with about 1ml of liquid karma and 2ml humega and just under 1ml of pure blend pro grow and fed that to my five little seedlings. Their cotyledons have yellowed and im willing to bet that its due to the light stress and them burning through nutrients faster than they can grow their roots out to find them

Pics from this morning. Looking better with the light moved up

Growth has been a hell of a lot faster since i moved the light up. From other grow journals it looks like my plants are about a week behind so i havent lost too much time. Still planning on vegging until late august, maybe even september.

The strawberry sour diesel that survived is droopy and still looks like its stressed. Everyone else is thriving which is funny because the ssd should have the most sativa genetics out of them all and therefore be the best suited to growing with higher light and temperatures. Its also worth noting the ssd has the broadest leaves so it may well possess strong indica traits. Time will tell.

starting from seed for me has always seemed the slowest part of the grow they seem to take forever I have a small 4 bulb t-5 fixture I use to start I really dig your led & later on I'm gonna go back & read your thread from the start you've moved along pretty fast you'll be putting out product in no time

horribleherk said:

starting from seed for me has always seemed the slowest part of the grow they seem to take forever I have a small 4 bulb t-5 fixture I use to start I really dig your led & later on I'm gonna go back & read your thread from the start you've moved along pretty fast you'll be putting out product in no time

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Thanks man, i would have continued updating this journal even if no one was watching but knowing that someone is makes me want to update even more.

I did cfl grows mostly until i moved up to a 150w hps, then i quit growing for a year and sold my hps. I used to start and finish under the same lights but with my hps setup my room was 7 feet tall.

With this new setup i started off thinking i was gonna wire up a bunch of little 3w leds and that id have to have my fixture inches from my plant. I built my room for that and then ended up scrapping the 3w diodes for cobs. Turns out the cobs need to be a lot further from the plants. My growth is way better now. I knew something was up when they were over a week out of the soil and barely even had a second leafset started.

Anywaus thanks for the words man, hope i dont ramble too much for you when you go to read through my posts

your diy light caught my interest right off the start & my thread isn't always the lively place in the world if nothing else I use my old threads for reference eventually I'm gonna have a led & im on the fence about a 315 cmh until I can afford a led right now I'm using a 250-400 switchable ballast but I'm wanting 600w. performance with a smaller utility bill the 315 cmh can equal about 500w. Of hps but although an improvement &affordable it's not a true led & the cheaper Chinese led's havent advanced to be close to the USA stuff yet I'm looking at amare ,California light works & some of the diy kits I'm wanting a 3x3 scrog

horribleherk said:

your diy light caught my interest right off the start & my thread isn't always the lively place in the world if nothing else I use my old threads for reference eventually I'm gonna have a led & im on the fence about a 315 cmh until I can afford a led right now I'm using a 250-400 switchable ballast but I'm wanting 600w. performance with a smaller utility bill the 315 cmh can equal about 500w. Of hps but although an improvement &affordable it's not a true led & the cheaper Chinese led's havent advanced to be close to the USA stuff yet I'm looking at amare ,California light works & some of the diy kits I'm wanting a 3x3 scrog

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Ill be sure to check your stuff out. I dont kniw much about cmh or how much they cost but my light cost me about 300 to build but i payed a little bit more for the convenience of getting everything from mouser and getting free shipping.

If you went with cheaper cobs like veros instead of the cree and cheaper drivers you could probably put together a 600w unit for, well i wanna say a dollar a watt but i cant say for sure.

Im under driving my cxb2530s by a fair bit, i think their max rating is 1400 ma so i could drive them harder and sacrifice some efficiency. Just an idea but you could always start off with less cobs and drive them harder, and then get drivers with a lower amperage later on.

I considered so many different configurations for my light. What i really would have loved to do would have been to run 6 cxb3590s at like 350ma or maybe 3070s and then i would really max out my efficienct but it woukd have cost easily twice as much.

Im not in a place to afford the minimum order requirement that alot of the cobs have either. If i can buy em one by one that great but i cant afford to buy packs of 10 especially when i do mixed spectrum grows.

Heres a look at my ducting system for my light. Nice horrible turbulence inducing s bend but its the best i can do in the space i have lol. You can really feel the difference in the heat coming from the exhaust from the light and the cooler air coming from my other two exhaust fans.

A lot of people say that pc fans struggle to move air through carbon filters and while i agree they certainly arent the best choice, they are surprisingly effective if you use them correctly. im running 4 x 3inch pc fans, 3 of them only 150ma and those are my exhaust fans, the 4th is 300ma and i use it as my intake because its the strongest one. All of them are fitted with ghetto rigged carbon filters that serve to keep bugs out of my grow, help reduce smell and light proof my in and outtake.

Ive also got 7 clones in the room now. Took some choice cuts off my outdoor just for fun. I use willow tea to root my cuttings. Ive never cloned outdoor plants before. I rigged up a little cloning tray with a tupperware container and plastic wrap. I pour the willow tea in the tupperware and poke holes for the cuttings so they csn sit in the tea while i transport them.

Then i just put them directly in soil and water with the willow tea. I use plastic bags for humidity domes because its convenient. You just cut the corners and the nozzle of a spray bottle fits right in. I mist with a dilute solution of the willow tea.

Willow tea works through a combination of the action of salicylic acid and indole butyric acid. Indole butyric acid is the main rooting hirmone i believe and salicylic acid has something to do with triggering the plants stress response so it goes into what im going to describe as like a ready state, i cant remember the specifics but the way i imagine it is its like the salicylic acid tells the plant to brace itself which helps it weather the stress of cloning.

I have willow trees all around my property so it makes no sense for me to buy cloning gel when i can just boil a handful of willow shoots

Here they are at 3 weeks old
In too row is the two white castles and the bottom row is the canadian cheese on the left and the remaining strawberry sour diesel.

For some reason my phones camera picked up the light reflecting off the leaves and it made it look like my plants are bleached when they are actually a decent green. I burnt them just a touch with the initial application if nutes but since then i dialed back what im giving them even more so. Just liquid karma and humega for now at about 1/8th the recommended dose

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ive also got some 2540s and 2530s

weed-whacker said:

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ive also got some 2540s and 2530s

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Thanks man, do you have any journals up? Id love to see what other people are doing with similar cobs. Part of why i started this journal was because i had a hard time finding any where people werent running 3590s or 3070s

Alright we are about a month in now and though my growth has picked up quite a bit since moving the light up, it still hasnt been optimal. Im entertaining a few different ideas as to whats going on with them.

They were certainly stressed and slightly bleached by the light when it was too close. The cotyledons and first two leafsets are showing signs of damage but all the growth that occured post light movement is nice and healthy.

They perk right up when i feed them so i suspect that they arent actually burned as i had thought earlier but instead are light damaged and somewhat nitrogen deficient.

Now i cant foresee the plant hanging on to the damaged leaves any longer than it needs too which is quite possibly why they dont appear to recover regardless of whether i increase feeding or decrease it.

They appear to be hungry and respond well to food so im going to continue on feeding. With only a week left in august im getting antsy due to the size of them. I was hoping theyd be about twice this size by now and im going to have to flip the lights pretty soon.

But wait, maybe theres still hope for a bigger yield after all! Time to send in the clones!

I went down and found some lovely root growth in 7/7 of the clones i took. 100% success rate ftw ive never had that happen before and im almost certain its a fluke even though i typically get about 80-90% success cloning with willow tea. Of course some of them could still die but they seem to be past the iffy stage now.

They are all female. I lucked out taking them about a week before my outdoor showed sex. Only two of my outdoor plants were male and they also happened to be the only two i didnt clone. Go figure. 3 are white voodoo and 4 are early vixen both from crop king seeds.

The strawberry sour diesel that remains is the sorriest looking of the lot. I think it needs some some tlc, probably just more finicky than my other strains. Possibly too indica dom to handle my sliglty less than optimal temps, ill keep trying to figure it out.

Wow those are the worst pics ive ever uploaded. Ill try and get some better ones later when the lights come back on