Validation/advices about my first grow space project

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TheClem

TheClem

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Hi everyone !

This will be a long post, as I'm here to validate the setup I'm planning to get.
Thanks to those among you who will be willing to take time to show me the way :)
The others, I still love you, peace fellow humans !

I'll try not to give too much details so this post stays readable (edit : it failed), feel free to ask any precision !
This will be my first grow, but as I have a strong tendency to overthink things, I've already researched a lot on the subject.
To summarize the project rapidely : I plan to put 4 big plants in a 120 x 120 cm tent, with a 300W LED full spectrum light.

Some things are already decided (and mainly ordered) : the lights and the seeds.

LIGHTS
Main full spectrum LED light : Mars Hydro TSW 2000
Additionnal UV lights (X2)

I've done a long and deep research about lights, so I'm pretty sure of this choice ;)
About the UV lights : I think I'll get 2 and hang them pretty high, to have a uniform exposure in the grow space, because I won't be able to center it, the main light being already in the center of the tent.


SEEDS
I'm not sure this is relevant to choose the gear, but in case you're curious, I bought :
- https://www.zamnesia.fr/1951-spliff-seeds-crystal-white-feminisee.html
- https://www.zamnesia.fr/6000-zamnesia-seeds-runtz-feminisee.html


Now, let's talk about the rest !
I got most of the links on Growshops.fr, but I can order somewhere else, I'm even thinking about going in an IRL grow shop, I'll see...


TENT
As I said, I think I'll take a 120 x 120 cm (4x4 feet) tent. This may be a little too big for 4 plants, but I want to have some space around for ventilation and such.
This one seems nice :


AERATION
Aeration is my main questioning right now. If you are willing to answer a single topic in this post, please answer this one :)
From what I read online and in books, I should aim to fully replace the air in my tent every 1 to 5 minutes.
For the size of tent I plan to get, that would mean a 120CFM (or 200 m3/h) extraction to replace air every minute.
I'm aware I'll have to add 25% to this if I decide to use a carbon filter (not decided yet, will be in my cave so...).
There won't be much duct, air will just be blowed out of the tent in a cave, not outside of the house.
I've read that with HPS lights, an intake is advised too, since the air needs replacement not only for CO2, but to keep the place cool too, so the air flow have to be efficient.
I didn't find many informations about tents with LED lights tho... I'm pretty sure it has to differ since the heat output is far from the same (500 BTU for my light).
So, here's the question : do you think I'll need an intake with the tent and light I'm planning to get ? I think a passive intake with a 100-150 CFM extraction would be enough ?
If a passive intake is enough, one more question : would you use a filter of some kind on the passive intake, to avoid contamination with god knows what ?

About the gear, it seems there is 2 different kind of ventilation :
- Duct ventilation (cheaper), like this :
- Or "proper" extractors, like this :
Would a duct ventilation be enough (if the CFM is enough of course) ? Or is there any reason I can't use only one of these and should get a proper extractor ?

About internal ventilation, I'm aware this is required too, I'll get one or too fans like this :


POTS
About the pots, I've heard Airpots and such (pots with holes and none cylindrical shape) are a must to avoid roots to grow in circle following the edge of the pot, and to maximize roots oxygenation. So I think I'll get that kind of thing.

But I'm really hesitating on the size... Should I get 7, 10, even 20 liters pots ?
I can afford to have 20L pots, since I'm planning to pu only 4 plants. That would mean pots will take a 70 x 70 cm space in my 120 x 120 tent.
But won't 20L pots allow the plants to grow too much ? won't they become too big for the space I've got (mainly the 200cm height limit) ?


SOIL / FERTILIZER
I've heard a lot of good things about BioBizz, plus their fertilizers line is 100% natural.
So I'm thinking about getting :
- Soil : https://www.biobizz.com/producto/allmix/
- Fertilizers :


MONITORING / CONTROL

It is apparently very important to only give water at a 6.5 PH, so I'll get a PH-meter and PH modifiers :




I was wondering if getting one of these to control the soil itself would be a good idea :
What do you think ? it can display PH and humidity in the soil. So maybe it can help with knowing when to water ?

I know some people get an EC tester too, to control the amount of nutriments in the water (I've got the datas about what EC you should aim at what stage of growth)

Since I plan to use the BioBizz fertilizers, and they have a precise dosage calandar, wouldn't it be a bit overkill to control it futher with an EC meter ?
Would you get one anyway and control water+fertilizers mix with it, just to be sure ?


ABOUT CO2
This is the one thing I didn't research much for now... I've seen that you can add CO2 to your grow space to optimize growth.
If I understood correctly, CO2 supplementation is usefull (necessary even ?) if you've got more than 1000 PAR on the plants.
Would some passive thing like this be any beneficial ? or is it completely useless ?

I'm not willing to spend money on a CO2 system, so if you tell me this kind of cheap CO2 supplementation is uselss, I'll drop this matter for now.


WELL ! Thanks for reading all this, I hope I'm not forgetting anything, any help or advices you can give me will be greatly appreciated :)
 
Oldguy71

Oldguy71

418
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I would get another 300w light for flowering. You’re at almost 19 watts/ foot, you want to be more like 30+. The uv is good but only need the last 1/3 of flower.
The fan, I run a 6” 390cfm inline fan for a 4x4 (120cm) tent. You can run a carbon filter with that fan if you decide to. More air exchange is better. Your internal fans look good.
Pots, I’d go 20l or even larger. More dirt means less adding nutrients and less hassle throughout the grow. Your plants won’t grow too big because of the pot size. That’s dependent on how long you veg for. Wider pots usually means naturally wider plants which means less trading and is good for indoor height restricted grows.
Ph meter, sorry, it’s crap. Blue lab is what most of us use. It’s a bit pricey but lasts for a long time, stays calibrated and reads quickly. Hanna is my second choice and apera premium would be my third. Seriously if a meter is under $50 it’s junk. Those $20-30 ones on amazon are $1 on alibaba. Same for the soil ph meter. Check and adjust your input water/solutions and check your run off occasionally.The up down solutions are fine. I use generals ph up and pool acid (sulphuric acid) for my ph down.
CO2, don’t bother with the cheap routes. A 4x4 tent full of plants can eat 50x more than those bags can create. Better off keeping fresh air flowing through the tent.
Well that’s my two cents hope it helps
 
Dr.B

Dr.B

1,074
163
Don't forget to factor in filter resistance. With my 400cfm in/out fans in a 5x5x7.5 tent I tend to turn over the air once a minute. Less in veg, more through flower...Thats just about 187 cfm on average days. I need to run my fans at an average of 60% intensity to achieve this airflow. A touch of resistance. The better in/out filters you invest in the better the airflow, and the lower the resistance. I can speak to phresh carbon filters quality, they wash out ok and don't run your fans into the ground. Next one I try is AC infinity's version... A tad cheaper. I gave up on intake filters and built my own a year or so ago. Effective, cheap, low maintenance. No air resistance. Uses furnace filters...

Hope some of that helps. I've been dabbing...
 
Aqua Man

Aqua Man

26,480
638
Co2 with air exchange is a no go IMO. The air exchange will bring in co2 levels of the room the tent sits in. If you add it will diffuse and be pumped out of the tent and diluted by the air in the room the tent sits in. The only real way to do this is to boost the co2 in the room the tents sits.

If you place the tent in the basement the co2 levels will be higher and no need to add co2. Typically a basement will sit around 800-1000ppm anyhow. But often times basmenta are cool and need supplemental heat... im which it's the same case and you need to heat the entire room that the tent sits in.

Temps, humidity all environmental factors you want to control should be looked at in the space you want to put the tent. It's just not feasible enough to control environmental parameters inside the tent when you are exchanging air.
 
TheClem

TheClem

4
3
Thanks for the answers guys :) my comments bellow :

I would get another 300w light for flowering. You’re at almost 19 watts/ foot, you want to be more like 30+. The uv is good but only need the last 1/3 of flower.

Seeing the PAR graph of the lamp at 12-18", I think it'll be enough for now for a start ;) I'll keep this in mind for later, but for now it'll be out of my budgeting.

Pots, I’d go 20l or even larger. More dirt means less adding nutrients and less hassle throughout the grow. Your plants won’t grow too big because of the pot size. That’s dependent on how long you veg for. Wider pots usually means naturally wider plants which means less trading and is good for indoor height restricted grows.

Oh OK, ! Good to know, I think I'll go with 20L pots then. Wider is good !

Ph meter, sorry, it’s crap. Blue lab is what most of us use. It’s a bit pricey but lasts for a long time, stays calibrated and reads quickly.

Okay, I'll consider to switch to a better PH meter... the good ones are pricey, maybe I'll take a cheap one at first and a better one later.
(I'll take a callibration flask anyway, to be sure it's calibrated).

CO2, don’t bother with the cheap routes. A 4x4 tent full of plants can eat 50x more than those bags can create. Better off keeping fresh air flowing through the tent.
Well that’s my two cents hope it helps

Yeah that's what I thought, thanks for the confirmation. In indeed helps thank you ;)

I gave up on intake filters and built my own a year or so ago. Effective, cheap, low maintenance. No air resistance. Uses furnace filters...

Interesting, since the intake filters I see are pretty expensive. Think I'll get a furnace filter too then :D
So, you think I still need 2 fans, for in and out, I can't have only one and have a passive intake ?

Co2 with air exchange is a no go IMO. The air exchange will bring in co2 levels of the room the tent sits in. If you add it will diffuse and be pumped out of the tent and diluted by the air in the room the tent sits in. The only real way to do this is to boost the co2 in the room the tents sits.
If you place the tent in the basement the co2 levels will be higher and no need to add co2. Typically a basement will sit around 800-1000ppm anyhow. But often times basmenta are cool and need supplemental heat... im which it's the same case and you need to heat the entire room that the tent sits in.
Temps, humidity all environmental factors you want to control should be looked at in the space you want to put the tent. It's just not feasible enough to control environmental parameters inside the tent when you are exchanging air.

Okay, I'll definitly drop the CO2 !
What you're saying about environnemental factors outside the tent is intereseting... I didn't though about it, but yeah, that makes sens xD
I checked both temperature and humidity in the cellar I'll put the tent in before considering to put it there, and currently, at night, I've 10°C and 55% humidty.
I was thinking the light would warm the tent up a little, and that maybe I could put a little space heater in the tent if I don't reach 20°C... but I now realise this is the whole cellar I'll have to warm up if I want 20+°C in the tent...

On the other hand, I recently saw pictures of someone successfully growing weed in a 12°C tent, so... I guess I'll be OK.
 
MIGrampaUSA

MIGrampaUSA

3,732
263
I would get another 300w light for flowering. You’re at almost 19 watts/ foot, you want to be more like 30+. The uv is good but only need the last 1/3 of flower.
The fan, I run a 6” 390cfm inline fan for a 4x4 (120cm) tent. You can run a carbon filter with that fan if you decide to. More air exchange is better. Your internal fans look good.
Pots, I’d go 20l or even larger. More dirt means less adding nutrients and less hassle throughout the grow. Your plants won’t grow too big because of the pot size. That’s dependent on how long you veg for. Wider pots usually means naturally wider plants which means less trading and is good for indoor height restricted grows.
Ph meter, sorry, it’s crap. Blue lab is what most of us use. It’s a bit pricey but lasts for a long time, stays calibrated and reads quickly. Hanna is my second choice and apera premium would be my third. Seriously if a meter is under $50 it’s junk. Those $20-30 ones on amazon are $1 on alibaba. Same for the soil ph meter. Check and adjust your input water/solutions and check your run off occasionally.The up down solutions are fine. I use generals ph up and pool acid (sulphuric acid) for my ph down.
CO2, don’t bother with the cheap routes. A 4x4 tent full of plants can eat 50x more than those bags can create. Better off keeping fresh air flowing through the tent.
Well that’s my two cents hope it helps

I second that. I'm running four 240w quantum boards in a 5 x 5. These boards have dimmers so I don't have to run them at 100%.

As for airflow ... I use a carbon filter + 120cfm exhaust fan and exhaust it into my "cave" (basement grow room). I use a 3 speed fan on medium for intake air. Intake air comes in towards the bottom and exhaust air is removed at the top. I'm not real concerned about odor. I live in a legal state and my next door neighbor has his own grow so all is good here.

Try not to "over-think" it. This plant is a weed that will grow most anywhere. This does not mean "don't take care of it" ... but spend more time worrying about the basics ... plenty of light, nutrient rich soil at the proper pH (or nutrient rich hydro water at the proper pH) ... make sure there are zero light leaks ... and that your timer functions without a flaw. Last but not least ... don't pick it too soon. Your grows will become more tuned in as you gain experience and add to your existing equipment.
 
Dr.B

Dr.B

1,074
163
Its all what works for you buds. Not everyobe can run 12 fans 24/7. I really like the pressure and environmental control that a matching input fan gives me.
 
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