A few questions and a lot of blabber

[Prodijay]

Hey guys, this is my first grow and I'd like to pick the brains of the more experienced growers for a moment...

So, I germinated my seeds using the paper towel method inside a propagator. After the taproot appeared I stuck them inside some small root riot cubes and left them for about 5 days. There wasn't many roots showing and the plants were about 3 or 4 inches long and beginning to show their first true leaves when I transplanted them into my hydro system with clay pebbles (I think this may have been a little early). My PH was measuring 6.4 & my nutrient solution measured about 240 including my tap water which measures around 70, so basically 170ppm worth of nutrients. I'm going to be giving the plants 20/4 light to dark ratio feeding the plants 3 x 15 minute feeds each day during lights on using a dripper system. Is this adequate?

Could anyone provide some sort of feeding time schedule for a plants entire life? I'll feed my plants 3 x 15 daily but when should I usually start to increase my feeds?

I'm currently using a 600w MH bulb but have the ballast set to 400w, I figured I'd increase it to 600w in a couple of weeks. I have the bulb quite far from the tips of the little plants, I'll put a picture at the bottom. Is it too close? too far? Could anyone give me a rough guide on distance from the plant a 400/600w bulb should be? Should the distance be kept the same in the flowering stage too?

Temps are kind of wild at the moment, even though I have a tower oscillating fan and 3 clip fans in the tent. One clip fan attached to the reflector & two in the corners, the tower fan is blowing on the plants on the lowest setting. I have a 5" exhaust fan but no intake fan, I always leave the two vents on the tent open. humidity has dropped to around 40%, I read RH should be around 70% during this stage so im way off! I've tried misting the room but that didnt work. Any advice on rising humidity %?


If you have any tips or advice on anything related to growing weed that I haven't asked then I'd be really glad to hear it!

please let me know if anything isn't looking right even though it's still really early on, thanks.

 

[fanleaf]

A humidifier is your best bet but you can help raise the RH a few points bu hanging a wet towel in front of your fan. Also, I'm not a hydro grower but it seems that maybe you pH'ed to a soil pH. I could be wrong but I think with your style of growing you want to be at about 5.8. Get a few hydro guys to back me on that but I'm pretty sure.

 

[Prodijay]

Thanks for your reply pal. I bought a humidifier from Amazon yesterday, it was about £16 but it looked more or less the same as all the others on there. I have it set to constantly mist my grow room but it only increases my RH by around 2%... Pathetic! I was hoping for an increase of atleast 20%. I'll try the wet towel method next. I read somewhere that anything under 6.5 is acceptable but I've been meaning to tweak it down a little anyway, cheers.

I think maybe I'll have to buy a bigger exhaust fan or install an intake fan to take care of the heat problem, which really sucks as I've already spent way more than I would of liked. I guess I could buy one of those cool tubes... I really want to crank up my lights to 400 or 600w so the plants get the most possible light but when I do the temps fly out of control

If I finally get my temps under control and cool down the grow room then that would automatically rise the RH right?

 

[Croatsan]

Hi Prodijay

No need for an intake fan, but a bigger exhaust would be a good idea. If you could manage a cooltube in there, that would be fantastic. Your lamp is generating a lot of heat in there. And you're right, that takes away lots of RH.

I would drip-feed them more often, like 6 times for 10 minutes.

5.8 for hydro is about right, but 6.4 is not that far off either.

A few, strategically placed, wet towels raised my RH for 12% in 4x4x7 grow space. Wet towels work.

 

[Prodijay]

My current exhaust fan is a 5" 280 m3h/164 cfm and my grow tent is 1.2 x 1.2 x 2m. Clearly this fan isn't powerful enough to suck the required amount of hot air away from my tent, could you recommend one that would be? I've seriously been thinking about getting a cool tube but from what I've gathered about how they work (carbon filter attached to fan which blows through ducting over the lamp and out of the tent) my problem would be that the tent is inside another room, it's cooler in the room than in the tent but if I have my exhaust ducting blowing all that hot air into the room then that would soon change and the hot air will just find its way back into the tent via the bottom vents...

I'll try the wet towels tomorrow and see if it brings my RH up any, thanks for the tip both.

 

[fanleaf]

A cool tube would make all the difference. Is your exhaust fan actually a blower made for exhausting air or just a fan? Your room is 80 cubic feet so 164 cfm blower should do ok. Thats e changing the air in the room 2 times per minute in theory lol. I had great luck with my 4" carbon scrubber/blower combo. Had adjustable blower speed too! It was rated just above 400cfm and was about $100 on ebay.

Thats an option

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[Cultivator]

im not sure a cooltube is necessary at all. I have stopped using them altogether as you lose a lot of light and its much simpler to cool regular shades.

Just run a good extraction fan attached to a carbon filter. get something that will air exchange 5 or 6 times per hour and that will keep temps down providing temps aren't high outside the space.

Aim to get your ph down to 5.8. Between 5.4-6.2 is fine and some fluctuation is good but 5.8 is a good base line where all nutrients will be available.

No need to add nutes just yet. Wait until they have their first set of real leaves then start base nute on 500ppm (500 conversion). Use quality base cute. I like advanced nutrients PH Perfect 3 part, it works great in hydro and gives healthy plants.

Your RH at 40 isn't the end of the world but don't let it get lower than that. Ive grown out a lot of plants in that range with good results. however ideally if you can get it around 60rh that would be better, it doesn't need to be super humid. you will find the plants start slow but then take off once they are adjusted to it.

Most important things are to make sure you have good air flow, good light and keep an eye on your ph in that set up.

 

[Croatsan]

You will never notice the loss of lumens with a cooltube. I ran a 600w HPS in a cooltube, and was able to get it to within 6 inches of the plant tps, with zero burning or bleaching - just make sure to get an extractor fan running air through it and it will beat a reflector hands down.

I have to agree with theengeneer on this.

There are, basically, two arguments against a cooltube and, IMO, both are weak:

1. The glass of a cooltube will reduce the light output.

True, but only for about 5%. On the other hand, cooltube allows you to position the lamp much closer to the plants than you'd be able to with a reflector. And I mean much closer. I can get a cooltube twice as close to the plants than the reflector. That's 100% closer. The inverse square law of light, definitely, works in my favor in this scenario.

2. The air blowing through a cooltube and over the bulb cools down the bulb and, therefore, reduces the light intensity.

Not true. The bulb is in a vacuum, so ambient air temperature outside of the bulb have absolutely no effect on the temperature of the inside of the bulb.

Also, a dedicated extraction line through a cooltube is always a better option than sucking it out through a carbon filter.

 

[Prodijay]

It's made for exhausting air, I bought it from Amazon as part of a kit including the carbon filter & ducting. If my fan is powerful enough to exchange the air in the room often enough then why is it still so damn hot in there? I don't think there's any need for an adjustable speed blower yet as my exhaust fan is on max and it still isn't adequate. If I purchase a higher cfm rated fan ill definitely look out for one. I find that there's more items on the American eBay at a better price too! If I could find your 400cfm rated fan on the UK version it would probably cost way more I would consider buying from the US eBay but the shipping price would be extortionate.

Is there a difference between a carbon filter and carbon scrubber?

 

[Prodijay]

Thanks for your reply, Cultivator.

I've had alot of contradicting replies regarding cool tubes and now I really don't know what to do. You said look for a fan which will exchange air 5 or 6 times per hour but another reply stated my current fan (164cfm) exchanges air in my grow tent around 2 times per minute! The temp outside my tent is currently about 25C and a little lower at night. Alot of people have said PH 5.8 is where I want to ideally be at so I'll try my best to get it there (which is harder than it sounds as PH down is so damn potent) my tap water usually starts at 8PH.

The first set of true leaves had already appeared, as you can see in my pictures. I started on nutes of 250ppm, are you sure 500ppm isn't a little high for young plants? Is that figure including tap water ppm or not? I already purchased GH flora series a while back, once it runs out ill try PH perfect 3 part, thanks.

I've all bit given up trying to raise RH, it really is a losing battle. As far as im aware if i reduce heat then RH will rise on it own so I think I'll concentrate on bringing down temps for now. I've heard cannabis plants can survive alot but I guess as a first time grower I'm just trying to be too precise.

So plants will grow healthy in temps of around 30C and 40RH all the way from seedling to bud?

 

[Prodijay]

I don't want to suck air OUT through my carbon filter I was thinking more of sucking air into it then through the fan over the lights and out. This way it would deal with smell and heat at the same time right? Like I said I don't think this is viable as im growing in a room within a room so it's important i don't fill the outside room with hot air. If you or anyone else could help me think of a way around this then that would be appreciated.

You seem to know your stuff, so I should opt for a cool tube over a bigger extraction fan?

The most frustrating thing is I know winter will be here before I figure out my heat/RH problems and that will bring it's own set of headaches, such as too cold or too humid. Ideally I'd like to figure out a way to keep temp down/RH up this summer so I know what I'm doing next summer. Then I can move on to battling winter problems.

 

[Croatsan]

If my fan is powerful enough to exchange the air in the room often enough then why is it still so damn hot in there? I don't think there's any need for an adjustable speed blower yet as my exhaust fan is on max and it still isn't adequate.

Because your bulb is still generating more heat than you're able to extract it. You have to reduce the heat.

Is there a difference between a carbon filter and carbon scrubber?

No. They're one and the same.

You said look for a fan which will exchange air 5 or 6 times per hour but another reply stated my current fan (164cfm) exchanges air in my grow tent around 2 times per minute!

That was a typo. Cultivator, probably, meant 5 or 6 times per minute.

The first set of true leaves had already appeared, as you can see in my pictures. I started on nutes of 250ppm, are you sure 500ppm isn't a little high for young plants?

It, definitely, is. For comparison, my plants are in the third week of flower and I'm @500ppm.

I don't want to suck air OUT through my carbon filter I was thinking more of sucking air into it then through the fan over the lights and out. This way it would deal with smell and heat at the same time right?

You do want to suck the air out through your carbon filter. It's always a better option than blowing it in.

I should opt for a cool tube over a bigger extraction fan?

Ideally, you should opt for both. But if you must choose, I'd go for a cooltube with a dedicated air line blowing through. Which means another inline fan in the configuration.

im growing in a room within a room so it's important i don't fill the outside room with hot air.

So am I. You have to have either, the intake, or the exhaust outside of the room. If you can manage both, that would be ideal. This is how I set it up:

 

[Cultivator]

Yes 5 or 6 times per minute not hour lol.

If you are having temps of 25 degrees outside of grow room thats the coolest you could possibly get the grow space using an extraction fan, however you are always going to running a little above that due to bulb giving off heat.

I don't want to start an argument about cooltubes as they will work. But having grown many thousands of plants under them I won't use them any more because you do lose light and you are more prevalent to bud rot. having said that my smallest room is 6x600w hps, and rest are atlas double that. Duct work can be a head ache for smell leaks also.

You def want to pull air through the filter but use as little duct work in the tent as possible as this also acts as a radiator.

There are no leaves on the plants in your pictures. just hold off nutes till there are real leaves then hit it will 500pm or 1.0ec of base nutrient. (my water is 0.3 ec so actually the pure nutrient would be 350ppm or 0.7ec)

good luck.

 

[Prodijay]

That's the problem, I currently can't figure out how to reduce heat/bring down temps. I'm amazed you can keep temps down with just one fan! Bravo

So my 164cfm rated exhaust fan isn't enough? I should disregard cultivators comment as it was most likely a typo?

500ppm for flowering... I read it should be double that during the flowering stage...

I have my carbon filter set up like yours, apparently sucking air out through a filter reduces a fans effectiveness by around 25%, maybe this could be the problem.

Ideally I would opt for a cool tube although getting a bigger extractor fan would provide less headaches as I don't really have anywhere to vent the hot air from the cool tube. I'm currently restricted to this one room for a few months. Where does your 'out' ducting from the cool tube lead to? Also, why are your lights so far away from your plants? Mine are much closer

Your setup looks awesome pal. Are you using a DWC setup?

 

[Prodijay]

So I should be looking for a fan about 2 or 3 x more powerful than my current one? I'm happy with anything under 30C as I hear plants won't grow if it's above that, is this true?

My ppm was like 250 but has increased to 265 in a little over a day so im just adding some ph'd water at 5.3 as my current ph is 6.5.

Here are some pics of my grow...
One shows what I consider to be the first true leaves. The other shows a different plant which looks to me to be having problems... Has anyone got a diagnosis for this? Apologises for the poor picture quality but the leaves look as if they're folding up and over into a taco like shape... Any ideas? The others are just showing my tent and filter/ducting

Also, how the hell do you keep temps down in a room with all those 600w lights? I can't even crank mine up to 400w otherwise the heat gets crazy. I guess im stuck on 250w for now

 

[Croatsan]

That's the problem, I currently can't figure out how to reduce heat/bring down temps. I'm amazed you can keep temps down with just one fan! Bravo

Actually, I've got two fans. Look at the photo again. One is extracting air out of the tent, and the other is blowing air through the cooltube.

So my 164cfm rated exhaust fan isn't enough? I should disregard cultivators comment as it was most likely a typo?

It was a typo. He'd confirmed it in his previous comment.

500ppm for flowering... I read it should be double that during the flowering stage...

During the end of the flowering stage, perhaps. Also, different strains have different needs.

I have my carbon filter set up like yours, apparently sucking air out through a filter reduces a fans effectiveness by around 25%, maybe this could be the problem.

I don't know the precise number but I doubt it's that much. Around 10-15% sounds more likely. But that's why you calculate that into the equation when buying an extractor fan.

I don't really have anywhere to vent the hot air from the cool tube. Where does your 'out' ducting from the cool tube lead to? Also, why are your lights so far away from your plants? Mine are much closer

It goes out of the window through a flex tube. My intake air goes in the same way. My exhaust is on top of the tent, blowing the extracted air inside of the room.

Are you using a DWC setup?

Yes. It's, technically, a RDWC (Recirculating Deep Water Culture) because I have an additional res outside of the tent.

Also, how the hell do you keep temps down in a room with all those 600w lights? I can't even crank mine up to 400w otherwise the heat gets crazy.

It's 2x400W. A dedicated air line through the cooltube helps significantly. But still, during the peak of summer, it was barely enough.

the leaves look as if they're folding up and over into a taco like shape... Any ideas?

That could well be because of the heat. On the other hand, it happened to me before and they've straightened up later.

 

[Prodijay]

I was just referring to the little oscillating fan you've got blowing on your plants pal, I have 2 oscillating fans & 3 clip fans and I still can't get the temps at the desired range.

I didn't see cultivators message before I replied. It's clear I need a bigger inline fan tho. A quick question about that... I seen a 6" inline fan with 660m3/h is this enough? Also, I have a 5" carbon filter and ducting. Could I still use these with this new fan? Will the fan slide right over the filter and ducting as they are an inch smaller.

Whats the difference between ducting and a flex tube?

I have a recirculating system but I've been thinking about getting some extra buckets once I get this grow room under control and starting up a DWC.

So I'll start with a bigger inline fan until I figure out a way to extract hot air from the cool tube. There is windows in the room quite close to the tent but I think it's quite suspicious having ducting hanging out of a bedroom window. Maybe weed is legal where you are, unfortunately that isn't the case here

I appreciate all the help given so far

 

[Croatsan]

I seen a 6" inline fan with 660m3/h is this enough? Also, I have a 5" carbon filter and ducting. Could I still use these with this new fan? Will the fan slide right over the filter and ducting as they are an inch smaller.

It's more than enough. For comparison, mine is 420m3/hr and it's doing a great job.

Whats the difference between ducting and a flex tube?

No difference.

I think it's quite suspicious having ducting hanging out of a bedroom window. Maybe weed is legal where you are, unfortunately that isn't the case here

It's not legal and you don't have to hang the ducting over the window. It would be sufficient to position it somewhere close to the window. You can do that, and it would still be within the room and not visible from the outside.

You've got to get the fresh air from the outside, somehow. Improvise

 

[fanleaf]

Before things were legal here I just bored a 4 inch hole through the outside wall and installed a dryer exhaust vent. That worked fantastic and would never draw attention

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[Croatsan]

I was thinking of doing the same thing during winter months, when I can't have my window open.