Get a Harvest Every 2 Weeks

[Al B. Fuct]

so on a 1000watter what cfm size fan do you recommend?

for what sized room?

i used to use a 4" on her....i think it was somewhere around 200cfm, do you think i should upgrade if im in hotter climates? especially in a cab huh?

Oh, do you mean for the cooltube? Any 150mm axial.

 

[LoudBlunts]

that light is in a cab. separate venting for room and light

 

[Al B. Fuct]

If there's a cooltube independently handling the heat from the lights, the ventilation system should be able to move the volume of the room in about 3 mins. In example, a 500cu ft room needs a blower that can move (500cu ft / 3min) 166CFM or more. It's one of the rare cases in cannabis growing where more is absolutely better.

Just about any 150mm axial blower will do for the cooltube, unless the ducting is longer than about 6m or has several sharp bends, where a centrifugal is a better choice.

In pre-installation tests with a 1000W HPS in a cooltube, with an Allvent A60 axial blower fitted without any duct to the cooltube, the output temp was 6.6C higher on the output end of the tube. With 3m of straight duct installed, the rise was 7.1C. When installed in my op, with the duct line stretched out to about 5m and with two 90 deg bends, the rise was 7.7C. As obstructions to airflow are introduced, the flow rate decreases and the air is in the cooltube for a slightly longer period, picking up more heat energy. However, the reduced flow rate also allows the Pyrex tube itself to pick up more heat, which it convects into the room airmass.

If making up your mind how to route a cooltube duct, your best choice is the one which yields the lowest EGT, thusly keeping the cooltube's glass as cool as possible.

 

[LoudBlunts]

well i have a 200cfm fan on the 1000watter....not too much of a problem now.

im just thinking about summer. especially if i JUST missed the temp by a few degrees. i guess it couldnt hurt to upgrade my 4" to a 6" on the fan to keep that light nice and cool


you agree sir?

 

[Al B. Fuct]

200cfm is plenty for a cooltube with a single 1000.

The Allvent A60, 150mm unit I am using on my pair of inline cooltubes which house a pair of 1000s is rated 192CFM.

You can work out the correct CFM size of the separate exhaust blower you should be running to vent the op by dividing your room size in cu ft by 3.

 

[southfloridasean]

Al where are you exhausting your cool tubes to? Are you exhausting to the outdoors or to the attic?

 

[We TaRdED]

Al where are you exhausting your cool tubes to? Are you exhausting to the outdoors or to the attic?

i know im not al b, but im pretty sure he said his intake was from outside and hes also exhausting the air outside too! it was some pages back somewhere in this never ending thread! sorry al, you can yell at me if you want! lol heh

 

[fromagebleu]

Thanks, Fuct, this is information I have really needed. I have a tiny space - about 5x6 feet, financial constraints, health issues, but could probably do two plants every two weeks with the right set-up. That's about 3/4 oz average per plant? I suppose it depends on the variety. But that's probably at least a couple of ounces per month as I calculate it.

This is my first grow (sort of lumped together with a second since I only got one female from seven seeds in my first) Can I turn my blooming OB into a clone mother when she is done blooming? How long would it take to go back to veg and be usable for cloning? I don't want to take one of my three pre-blooming females for a mother because I badly need stash. But suddenly maybe a better answer comes to me - I could clone from a lower branch of the largest female seedling and put it back into veg, right? And then keep it there, and when I am close to having the room, start clones from that. Am I thinking straight about this, noob that I am?

 

[stickyicky77]

i know im not al b, but im pretty sure he said his intake was from outside and hes also exhausting the air outside too! it was some pages back somewhere in this never ending thread! sorry al, you can yell at me if you want! lol heh

The cool tubes i have seen are water cooled and they work very well but you do have to have a small separate rez and pump to circulate the water through the hood.

 

[LoudBlunts]

The cool tubes i have seen are water cooled and they work very well but you do have to have a small separate rez and pump to circulate the water through the hood.

you dont necessarily have to watercool a cooltube to keep it cool

 

[Enigma]

Hey Al, I gotta quik question for ya.

How small can the net pots for clones get?

I'm thinking a 6" tall clone in a 2-3" pot sunk in a 4" PVC tube should hold enough for an aero op. I'm really trying to squeeze things into a 4'x4' area.

Enigma

 

[Al B. Fuct]

Al where are you exhausting your cool tubes to? Are you exhausting to the outdoors or to the attic?

I have a very unusual installation because I have a very unusual house. The op both sources air from and vents into a crawl space under the house. That crawl space happens to be the attic for the op, as it is above it. Is my op in a cave? Pretty darn close. It IS under the house and half its walls are naked bedrock. It'd be nearly impossible to explain properly without showing you photos of how my house is built... and how it is built is a deadly obvious clue as to where it is built... so I can't really put that sort of detail online here.

The volume of the crawlspace airmass is about 6000 cu ft. As bedrock is exposed in this crawlspace, the air temp in the crawlspace is between 14C-21C all year round. The large, 6000cu ft airmass soaks up the heat that I dump in the crawlspace and sinks it in the exposed bedrock.

i know im not al b, but im pretty sure he said his intake was from outside and hes also exhausting the air outside too! it was some pages back somewhere in this never ending thread! sorry al, you can yell at me if you want! lol heh

My actual comment was:

"I did opt for a closed loop, drawing cooling air for the tubes from outside the room's airmass and also dumping outside."

I intended to convey that the cooltubes get and dump their air outside the growroom's airmass- but not necessarily to outdoors per se.

OK, I'm yelling at you. Please don't fill in my blanks unless you're quoting from something I wrote. Mind, even that isn't an entirely safe bet. Sometimes I've changed a process or something... and may not have issued the ECN (engineering change notice) as yet!

Thanks, Fuct, this is information I have really needed. I have a tiny space - about 5x6 feet, financial constraints, health issues, but could probably do two plants every two weeks with the right set-up. That's about 3/4 oz average per plant? I suppose it depends on the variety. But that's probably at least a couple of ounces per month as I calculate it.

Depends as much on the op and you as the DNA, but good genes put you miles ahead. If the op maintains a 24-26C @ 30-50% RH and you are consistent in your maintenance regime, 3/4oz per (presuming 400HPS flowering 8 indica dominant hybrid plants) is probably low once you're in the swing of things.

This is my first grow (sort of lumped together with a second since I only got one female from seven seeds in my first) Can I turn my blooming OB into a clone mother when she is done blooming? How long would it take to go back to veg and be usable for cloning? I don't want to take one of my three pre-blooming females for a mother because I badly need stash. But suddenly maybe a better answer comes to me - I could clone from a lower branch of the largest female seedling and put it back into veg, right? And then keep it there, and when I am close to having the room, start clones from that. Am I thinking straight about this, noob that I am?

Revegging a plant previously in flower takes a LONG time, 6-8 weeks before growth fully returns to a normal vegetative habit. If you think you're low on weed now, you'll be much more annoyed while waiting for a plant to reveg.

Your best bet is to take cuttings from your plants which you are keeping in veg at present and establish the mum/s you need.

 

[Al B. Fuct]

The cool tubes i have seen are water cooled and they work very well but you do have to have a small separate rez and pump to circulate the water through the hood.

I'm sure water cooled tubes would work very well, but if given the choice between air cooled and water cooled cooltubes, I'd pick the air cooled type every time on the basis of reliability and low maintenance.

Water cooled types would require tubing with lots of connections, a pump capable of sufficient head (lift) to get water from the tank to the cooltube and then would require some sort of fungal inhibitor in the res to keep anything from growing in the cooling system.

The only maintenance required with air cooled cooltubes is dusting out the cooltube and cleaning with window cleaner every couple of months. No tanks to fill, no tubing connections to leak, no pump to fail- and water pumps are lots and LOTS less reliable than a 150mm axial blower.

Hey Al, I gotta quik question for ya.

How small can the net pots for clones get?

I'm thinking a 6" tall clone in a 2-3" pot sunk in a 4" PVC tube should hold enough for an aero op. I'm really trying to squeeze things into a 4'x4' area.

Having a hard time visualising what you want to do, sorry.

 

[Enigma]

Having a hard time visualising what you want to do, sorry.

Ok, here is some more detail:

4' x 4' floor space

6.5' height

Using 10 4" PVC square fence posts horizontally. Installing 3-3.5" net pots in a aero op. Squeezing every inch out of this space for clones not taller than 6" when transplanted. This way there will be new smoke every 1-2 weeks.

Your thoughts?



Enigma

 

[Al B. Fuct]

Ok, here is some more detail:

4' x 4' floor space

6.5' height

Using 10 4" PVC square fence posts horizontally. Installing 3-3.5" net pots in a aero op. Squeezing every inch out of this space for clones not taller than 6" when transplanted.

Ah, ok, I see what you're up to.

The only drawback I can see is that plants likely won't be mobile within the op. They will have to stay put until harvest as their rootmasses will probably knit in your 100mm/4" square aero chamber. Even if you take some measures to stop knitting, roots growing without media are rather easy to damage and won't like being moved. It's really handy to be able to move plants around in an op to even out growth and for plant maintenance.

I think what you will end up with will work great, but will be classifiable a bit more accurately as NFT rather than aero.

The main difference between aero, DWC and NFT is the water level.

True aero systems use root chambers tall enough to keep the roots from dipping into pooled nute soln below them. The roots are irrigated only by sprayers or (far preferably) by a nute mist created with air stones in a pool of nutes below the roots and contained in a rather large chamber.

NFT uses a very shallow water level in a long channel or tube which is sloped to allow water to drain out the other end from the feed.

DWC submerges the roots fully in a constantly aerated solution.

In a 4" square tube, it'll make little difference whether you have sprayers spaced between netpots or if you just feed nute soln at one end of the square pipe and let it gravity feed down the tube.

Whether operated as aero or NFT, handwatering the netpots of clay pellets from the top will be needed for the first 1-2 weeks or until roots are well through the netpot bottoms and can contact either a sprayed or gravity fed stream of nutes.

If you want to do aero, I'd consider using something a larger than 4" square tube for the aero chamber- perhaps 150mm or larger round PVC stormdrain pipe; something large enough to have a couple inches of water pooled in the bottom and some airstones/bubble curtains in the pooled nute soln to create the mist. The tubes would have to be fed from a nute res to have adequate reserves for a couple of weeks tank life.

 

[We TaRdED]

Ok, here is some more detail:

4' x 4' floor space

6.5' height

Using 10 4" PVC square fence posts horizontally. Installing 3-3.5" net pots in a aero op. Squeezing every inch out of this space for clones not taller than 6" when transplanted. This way there will be new smoke every 1-2 weeks.

Your thoughts?



Enigma

i thought about the same thing, but you have to keep the tds at a intermediate level, as not to over fert your little clones and keep it high enough to provide sufficient nutes to the older plants. whats your thoughts on that? im no expert, but thats one flaw i can see, maybe its not a big problem, let me know what you think. al b fuct, you can answer that too. ty guys

also you might have some funky light levels going on, with the heights of the lights if you doing it all in the same entity. the smaller the unit, the hairier it would seem to be.

 

[Al B. Fuct]

Since I failed to do so in the last post, I really have to reiterate my hatred for any hydro system which pumps nutrient solution through a small aperture like a sprayer or mister. These critters will crust up with nute salts unless cleaned frequently, about every other day.

If your system is organised so you can't see the water spray action, you'll have to pull each sprayer out to check and clean them.

I've said it lots of times- I'm a stoned slacker. I don't really want to work very hard on my op. I want to be able to leave it for at least 3-4 days at a time if I get a slack-attack.

Flood systems do not push nutes through small apertures and simply can't clog. Plants in pots of absorbent media have a constant backup water supply and thus are much more tolerant of water pump failures than medialess systems. Flood systems can go weeks without tank aeration but work lots better with it than without.

However, flood systems with plants in pots of absorbent media do not allow maximum oxygenation of roots, particularly in highly absorbent media like rockwool floc, which can hold so much water that the water can lose all its dissolved O2 before the plant can soak up all the water in the media. This is why I switched to the much less absorbent Fytocell material. I sacrificed some water supply backup time to permit more frequent flooding with oxygenated nutes.

Yes, aero, NFT and DWC all have the potential to outyield pots of absorbent media in a flood system. However, the medialess systems also can be prone to failures which can cause loss of an entire batch of plants. Takes a long time for the somewhat reduced yields from a pot-based flood system to equal the loss of an entire batch.

If you have the attention span and energy for the frequent checks required, medialess systems are for you. If you're as slack as I am, something with some safeties built in might better at the compromise of absolute max yield per square foot.

 

[Al B. Fuct]

i thought about the same thing, but you have to keep the tds at a intermediate level, as not to over fert your little clones and keep it high enough to provide sufficient nutes to the older plants. whats your thoughts on that? im no expert, but thats one flaw i can see, maybe its not a big problem, let me know what you think. al b fuct, you can answer that too. ty guys

I run all my tanks at 1400ppm, even tank 1, which supplies clones just put in to the flowering area. They don't seem to care about jumping from the pH adjusted water with no nutes they were getting in the clonebox to the 1400ppm flowering nute soln.

also you might have some funky light levels going on, with the heights of the lights if you doing it all in the same entity. the smaller the unit, the hairier it would seem to be.

This is why it's nice to have plants in pots of media. Easy to pick them up and move them around and put them in positions closer to the light if need be. If you're using a double parabola/batwing reflector, you can spread light out really rather evenly over a rectangular growing space, but the space just below the lamp tube will always get the most intense light.

 

[We TaRdED]

ive heard that ppl just leave their pumps going 24/7 through the misters and they said that they have never had a clogged jet as long as you keep spraying nute solution through it. and if you going to stop using the system for w/e reason, flush it with water real good and/or use some flushing agent. any thoughts abuot that al? thanks my aussie friend!

 

[Al B. Fuct]

ive heard that ppl just leave their pumps going 24/7 through the misters and they said that they have never had a clogged jet as long as you keep spraying nute solution through it. and if you going to stop using the system for w/e reason, flush it with water real good and/or use some flushing agent. any thoughts abuot that al? thanks my aussie friend!

Flowering systems should be without irrigation when the lights are off, so there's 12h/day that the sprayers can dry out. Watering during lights-off can invite root probs, but a lot of nute soln oxygenation should prevent too many problems in that regard.

I agree that running the sprayers continuously would reduce the likelihood of clogs. However, you should have a filter on the pump inlet to prevent precipitated nute salts or other particulates present in the reservoir from being pumped into the spray apertures.

If one must flush a sprayer based system, to truly remove all minerals, one would have to use distilled water. Most municipal tapwater has enough dissolved mineral content to eventually create problems all by itself.