Growing Mother Plants

[Uk1nation]

hello all,

my question is: can i have the extraction fan running only during the light cycle and not 24hrs??

have a 120x240x200 tent.... as i aint flowering the plants would i still need a 5" fan even though i have only 1 600watt hps light and 2x 250watt CFL (for cuttings) ????

Hope to hear from you soon

many thanks

UK1nation

 

[JJ Bones]

You want air circulation 24/7, constant air exchange is important to healthy indoor gardens.

I don't know enough about the fan question to answer it, I don't fully understand.

 

[LivenBurn]

if the only way to keep circulation going & heat down is your extraction fan-- then 24/7. if you have a passive circulation system or you're in an open area or are able to open the tent-- you can probably get away with using an oscillating fan to keep everything moving when lights out

 

[Fuzzy Duck]

Its best to keep an extraction/exhaust fan running 24/7 for better air circulation


If ya turn off the exhaust/extraction fan in the dark period/lights off ya see a massive humidity spike & this can lead to powdery mildew & bud rot problems... ya really don't want that !

Can be observed with ones of those humdity reading gadgits tho, if its has low & high recording function to it or by reading the device before lights go off & just before lights come on


A tent that size will more likely require 2 X 600w bulbs for optimal coverage of lighting & that a 5" exhaust/extraction fan is below average... more likely aiming at a 8" inline fan...

However with just one 600w bulb or just the 2 X 250w bulbs for clones, ya more likely get away with it !




A large tent like that ya still looking at 2 X 600w bulbs & air cooled hoods would be a good option to control heat issue's if any do occur ?

As 600w bulb will roughly cover an area of 4' by 4' at best.

A 250 bulb will cover a 2' by 2' being pretty optimal.

This all depends on wattage of bulb divided by square foot coverage... thats a reasonable old school calculation which appears to hold true to present day but does not include the rule of the square law light effect over distance to diminshing returns of hanging height.

Optimal wattage per square foot is 65w, average 50w & just about get away with growing 30w this directly effects end yield when using HPS or what ever bulb type ya use for flowering tho...



Ultimately if you want to reduce over all head cost for vegging T5/T8 tubes of 6500/6400k will be pretty good... saves buying loads of ballests & a tad cheaper to run on electric than MH plus ballest...

 

[elious]

Ventilation is a must!! You really don't want to work that hard, dedicate all that time and money just to have mold screw it all up near the end of the show. And thats when its most important. 600watts is going to put off some pretty serious heat too. Its nice to have the fans cool everything off after the lights go out. Especially when you're doing DWC, aero, ebb & flow, etc...

 

[mountaingoat]

Agreed with previous posters go for ventilation possible have the fan go on a lower speed at points but try to keep the flow going all the time.