Get a Harvest Every 2 Weeks

I hope that's enough.

As mentioned, black duct (or alu type painted black inside) might help prevent back conduction. Bends between the two lamps will help trap light... but they will impede airflow. If there's several 90s, it may call for a centrif blower. The cost of a 150mm centrif would easily exceed the cost of two 150mm axials. If there's enough obstruction to cause problems, the surfaces of the cooltubes will get hot and allow heat to transfer into the room's airmass. If that's the case, it will be most practical and cost effective to split the systems and use two 150mm blowers.

As mentioned last week, I did get a sulfur 'burner' to address the powdery mildew. Spraying isn't keeping it down.



It's a stainless can with a perhaps 50-100W heating element and a steel cup for powdered sulfur.



Does not burn but rather melts and evaporates powdered sulfur (avail from garden aisle in the local megahardware) to combat powdery mildew.

Absolutely NO instructions included... not so much as a power rating for the heating element.

Did a little quick research and found a suggestion to start at 10mins/day and back down if tip burn occurs. Started off with about 25g of sulfur in the cup; it melted that amount with no trouble. Will have to keep an eye on it to see how much it will use. The powdered sulfur was cheap, $5 for 500g.

Trying it initially running on a timer for 10 mins/day, with the runtime in the middle of the dark cycle to assure the main exhaust blower is not running when the 'burner' is on. If I see tip burn, I'll back it down to 7-8.

Al B. Fuct said:

Axials are not very good at pushing air into a high static pressure caused by obstructions, like a filter. Air pressure just leaks backward between the axial fan's blades when the limit is reached. The blades 'stall' like an airplane wing and don't move much air. Thus the CFM ratings of an axial pushing into a carbon filter simply are not reliable. You might be getting 10-20% of the rated flow. If there's a carbon filter in the duct, you'll want to get a centrif blower.

Intake fans on the other hand, when paired with a centrif exhaust blower, are just plain loafing. They can be dirt-common hardware store 'duct fan' axials, 150mm is common. The intake capacity rating should be about 80-90% of the exhaust blower rating to keep the room at negative pressure. This way, any small gaps or air leaks become air inlets. If the room were at positive pressure, they would be exhausts, allowing air out of the room without going through the carbon filter. If the room is at slightly negative pressure, all air leaving the grow will go through your carbon filter. For low cost, use a pair of smaller, cheap axials whose added CFM ratings are about 80-90% the CFM of the exhaust blower.



Yes, but I have my suspicions that's close to the upper limit. You must be planning to take a LOT of cuttings.

Click to expand...

i think you misunderstood, hydroponic supplies and equipment for hydroponic grow systems : Canadian Wholesale Hydroponics. 1 (877) 226-4769 the 6" can fan will be the exhaust fan. on it will be 3 cool tubes and a filter, the duct and cooltubes will be in a straight run to keep the cfm up and not lose and power or minimal anyway. it is 440 cfm with about a 14 foot run(STRAIGHT) with a 400 cfm filter on the other end.

for intake i have a hole to the upstairs which will be intake it is about6x10 and was gonna be passive. instead i was gonna throw in a 190 cfm squirrel cage to boost air in.

are you saying nix the squirrel cage to help keep the pressure negative? or should i use the squirrel cage? i do plan on sealing the room AIR TIGHT if possible. im lucky enuf to build from scratch in a basement so i can frame the room and white plastic and tuck tape the whole room.


for cuttings, ya i have the setup ive been referring to for the most part but im also setting up a bigger op with a friend with 4 4x4 tables for flowering area so that will be about 50-60 cuttings every 2 weeks. dont want to take more than 6 a plant really so 14 plants gives me up to 80 cuttings for new and mom replacement and what not.

cmak40 said:

i think you misunderstood, hydroponic supplies and equipment for hydroponic grow systems : Canadian Wholesale Hydroponics. 1 (877) 226-4769 the 6" can fan will be the exhaust fan. on it will be 3 cool tubes and a filter, the duct and cooltubes will be in a straight run to keep the cfm up and not lose and power or minimal anyway. it is 440 cfm with about a 14 foot run(STRAIGHT) with a 400 cfm filter on the other end.

Click to expand...

...ok- I'll have one more go at it. Did the best I could with your query phrased as it was.

The 'can fan' is an axial and should not be used with a carbon filter. It may be rated 1023CFM but I'd be surprised if it delivered more than 20% of that figure with a carbon filter inline. It is also 10" (255mm) dia, about 100mm larger than the dia of most cooltubes. Use a 150mm axial on the cooltubes, with no filter and a closed air path.

Your cooltube blower must be independent of the room's main exhaust blower. You can not use a thermostat on the blower driving the cooltubes. It must run at all times during lights-on, +15min after shutoff to cool down the cooltubes before stopping airflow. The effect of trying to use the cooltube blower as the main exhaust will be poor regulation of the room's airmass temp. Room air temp will be intake air temp plus about 2-3C.

The cooltubes should run on a closed air circuit, sourcing and dumping air outside the room's airmass. If this is done, the cooltube air will not require scent treatment.

With separate cooltube and main exhaust blowers, it's easy to expect the room will stay at your 25C setpoint +/- 1C (or better).

are you saying nix the squirrel cage to help keep the pressure negative? or should i use the squirrel cage? i do plan on sealing the room AIR TIGHT if possible. im lucky enuf to build from scratch in a basement so i can frame the room and white plastic and tuck tape the whole room.

Click to expand...

First, you need to rework the plan so you have separate cooltube and main exhaust blowers. Then you can set about selecting an intake blower.

Duct tape these days just ain't what it used to be. If you have a line on top quality duct tape, the way it USED to be made, where its main purpose was to hold HVAC ducting together, it may work OK. Otherwise, if it's the new style stuff, it will come off in just a few weeks when exposed to warm air and humidity.

I hang panda film by cutting 6-8" lengths of scrap wood and running a couple of screws through it, pinching the panda film. If I have to join panels of panda film, I glue them with silicone sealant and duct tape them as needed to hold things in place until the silicone sets up. The duct tape will come off in short order, but when the silicone dries, it's all good.

I like metal repair tape and gaffer's tape these days. Real EB-Green is great if you can find it.

3M makes some useful specialty tapes:

Maintenance > Utility Tapes - GlobalIndustrial.com

Gratuitous op shot of the day.



Widest shot I can get without a fish-eye lens.

Maccabee said:

I like metal repair tape and gaffer's tape these days. Real EB-Green is great if you can find it.

Click to expand...

Thanks for that, Mac. Great research as usual.

Al B. Fuct said:

Gratuitous op shot of the day.



Widest shot I can get without a fish-eye lens.

Click to expand...

nice shot al

thats the fullest one i have seen yet

ty my aussie friend

yep, the camera was up over my head, jammed into the upper corner of the room. The mother plants are in a subdivided area just to the left.



Like the inverted fans? Just removed the crossbar stand and screwed their bases to a ceiling joist. Don't have to trip over the fan stands anymore. They have been running inverted for about 8 weeks now, all good. I did disassemble the fans and greased up their oscillation mechanisms and pivot axles before I put them up.

Thats an awesome idea with the fans!

oh yeah stang, I was going to mention to you that you should work in some clearance for circ fans on the far ends of your pairs of trays. The 'hanging from the ceiling' trick will save you a bit of space but you still have to have room to swing the fans without taking up the space above the trays- plants need that space.

I tried some compact tower fans but they did not like being run inverted. Their osc mechanisms quit after a month or so. I had to scoot my trays away from the wall on the far end to make room for some common $14, 40cm osc circ fans, but not as much as if the fans were standing on the floor. The tower fans were twice the price and I know I have to replace osc circ fans yearly, so I just made room for them and bought in a stock of about 20. Sucks that I didn't design in enough space from the get-go for the cheap traditional type fans. Hopefully you can catch this before you start setting up, unlike me.

Lasko makes a 16" 3-speed wall-mount oscillating fan--I think it's about $35 or 40.
Mounts closer to the wall than you could an inverted standard fan, good if space is really a premium for you.

Eagle eyes will note a pair of 1000HPS ballasts in the upper left. I have four 1000 ballasts- two are mounted outside the room to keep their heat outside of the room's airmass in summer. Pictured are the winter ballasts. I need all the heat I can get when the intake air in winter drops to 12C. Moving the cabling beats hell out of moving these ballasts- these fuckers are HEAVY, 25kg easy.

Maccabee said:

Lasko makes a 16" 3-speed wall-mount oscillating fan--I think it's about $35 or 40.
Mounts closer to the wall than you could an inverted standard fan, good if space is really a premium for you.

Click to expand...

Thanks for that, Mac.

I've seen box fans which accomplish oscillation by way of a disc-shaped rotating vane on the front of the unit. The body of the fan doesn't move- only the vane rotates. These are only about 100mm thick and can be placed within about 50mm of the wall. Unfortunately, they're too pricey for yearly replacement. Cheapest ones I could find locally were close to $50.

Well and truly off-topic, but while I have your attention... check out this video of the April Fools' Day raids on Nimbin.

Al B. Fuct said:

Thanks for that, Mac.

I've seen box fans which accomplish oscillation by way of a disc-shaped rotating vane on the front of the unit. The body of the fan doesn't move- only the vane rotates. These are only about 100mm thick and can be placed within about 50mm of the wall. Unfortunately, they're too pricey for yearly replacement. Cheapest ones I could find locally were close to $50.

Click to expand...

Interesting! Found this:

Soleus FB1-30-20 12" Box Fan with Rotating Grill
$24

Could be secured (screws through feet?) to a shelf, ceiling or wall sideways for a fairly easy wall mount I think I think.

They have a bunch of cheap fans, actually. Their soft blade fan (8", $16) affords interesting space saving possibilities too.

two questions for ya al...

i modded a trash can on wheels for a res. i put a drain on her and hose...but duh! the hose doesnt curve downwards.... what pump can i put in there? i remember you mentioning before in your drain threads. would i use the pumps for flood and drain settings? and btw...what is the 'regular' name in brandname stores like walmart, petsmart, lowes, hd instead of the notorious hydro names? wouldnt i just put the pump at the bottom, turn the pump on when i want to use my hose? as far as the pump....is there any pump that can use side pumping like instead of having the tube upwards? i already cut the drain at the bottom of the trash can. fucking A!!! wish i would put the drain or hole up like midway of the trash can so i could route the hose from the pump to the hole..... wonder what kinda fucking tee's imma have to get to make it work...any ideas?

second... IYO, what is the best way to aerate? i hear all this shit about bubblecurtains, airstones, bubblestones, air diffusers....air pumps with air lines running thru the res....what is your opinion on the best and way?

Gday Al,

Really enjoy your tutorials mate, much obliged. Seen them on OS to, well done.

I live fairly close to Nimbin, what an overkill! I think the problem there lately is a lot of young blokes hassling tourists, fighting, and selling stuff heavier than weed. Perhaps they should of done their raid later in the day and targeted those clowns rather than the 'Embassy' and Museum, dorks.

Keep up the good work Al.

wow I don't keep up with the thread for one day, and come back to these new additions. Doing an incredible job with the grow and the thread Al.

LoudBlunts said:

fucking A!!! wish i would put the drain or hole up like midway of the trash can so i could route the hose from the pump to the hole..... wonder what kinda fucking tee's imma have to get to make it work...any ideas?

second... IYO, what is the best way to aerate? i heard al talk about using bubble curtains.. is that what you recommend al? bubblecurtains

Click to expand...

whats good LB?

Pond and Filter Tank Bulkhead Fitting - 2" - eBay (item 360039047121 end time May-01-08 15:26:27 PDT)

if you want to put a line midway in the trash can you might want to look into getting a bulkhead..

ive never used one, but i think thats what i would use for that job...

just my 2 pennies..