First Attic Grow, Northern Europe. Sweet Deep Grapefruit

Hi all,
I've been reading the forums for a couple of weeks now and have been delighted to find so much information. Thanks!

I'm attempting an attic grow, using feminized Sweet Deep Grapefruit seeds from Dinafem. As of today I have five seeds cracked, planted, and under the lights

I've come across some issues in building the grow room. Some I've addressed already, but I'd like the opinions of more experienced growers...

My set up:
Homebox S (80x80x160cm)
400 Watt HPS (Philips Master Greenpower CG T)
Lumatek 400w adjustable ballast
100 TT 4" exhaust fan

Issue #1 - Ambient Temperature

The attic is poorly insulated, and it's fucking freezing outside. Without lights or a source of heat the temp drops to under 40 sometimes at night. I've ordered one of these tubular heaters:

http://www.ebay.ie/itm/45-Watt-1FT-Tubular-Heater-Low-Power-c-w-1-5M-Flex-Plug-/250980800639?pt=UK_Home_Garden_Hearing_Cooling_Air&hash=item3a6f9f187f

and one of these thermostats:

http://www.ebay.ie/itm/Temperature-Controller-Thermostat-Aquarium-STC1000-Incubator-Cold-Chain-Temp-/190794935766?pt=UK_Sound_Vision_Other&hash=item2c6c43add6.

That should allow me to regulate the temperature automatically. What's a good night time temperature? Is the difference between night and day temperatures more important during the flowering stage? Should I get a cover for the heater, as in, is it likely to be a firehazard?

Issue #2 - Lights too hot for my plants

So until the heater arrives I'm running the light at 400 watts 24 hours a day. This keeps the temperature of the grow room from dropping too low. But I'm concerned that the young plants will burn under this extremely strong light. I've jerry-rigged a heat shield, using a 2 gallon pot covered in aluminum foil, suspended between the light and the plants. this was a recommendation from the guy in the grow shop, who said that initially the plants would only need ambient light to develop. Opinions? I have the option with the ballast to run the HPS at 250 watts, will this still be too hot for my plants in direct light? The light is 3.5-4' away from the pots.

Issue # 3 - Length of intake ducting

The attic is in rented accommodation so I can't go poking big holes in the roof. I did manage to find an opening underneath the eaves, and have run some ducting from there to my tent to deliver fresh air from outside. This journey is 12 feet, with a 90 degree bend towards the end. I'm using a passive intake, and an active exhaust. Some questions:
Is the passive intake journey too long? Will it need a fan to boost intake? Or will the exhaust fan create enough draft to suck it in?
Once I have my heating issues solved, should I be running the fans all the time? Or is this a waste of energy?
I presume that my ventilation requirements are minimal now but will grow exponentially as the plants do. Have I got this wrong?

Issue #4 - Exhaust into attic

I'm currently pulling fresh air from outside the house with the passive intake, but I'm exhausting into the attic itself. Are there any issues with this? For now I thought it would help with the ambient temperature being so low, but obviously I'll have the opposite problem in the summer. I'll be up there every day for about half an hour, during which time the door is open and air can circulate. Is this enough? Maybe run a desk fan when the door to the attic is open to help move the air from the house up there?

All advice would be very much appreciated.

I'll get some pictures up when I have time.

Also if anyone could point me in the way of a good thread on humidity control that would be great.

Thanks in advance,
completeretard.

right now i would keep outside fan off i dont think 3.5 to 4 is not too close to hurt plants unless its to hot i have used it before and if its to hot turn out side air on and piont it at light to cool heat down but not at plants rember plants like 76 degrees younger ones little warmer and in summer you will probaly have problems if the roofs not vented or has no vents on the out sidewall walls next to roof for cross ventalation. even now with light on and heat starting up there start looking for moister like condintion

Would a desk fan mid way up the tent achieve the same goal?
When you say you would keep the outside fan off, do you mean the exhaust fan or just the intake?

Thanks for the advice.

intake you dont want cold air blowing on new seedling but if its to hot there use it for cooling it down by pionting it tores the light to help cool it down a little but check first and after to make sure the temps ok around 75-80 will be ok leave exhaust fan on do to small room will probaly overheat

Thanks again

Couple of pictures.

There's what looks like some damage on the largest plant (bottom left hand corner pot). One of its leaves has a crease or bend in it. Anyone seen this before?

Otherwise I think they look alright. Every time I exhaust (15 minutes every 3 hours), the humidity drops to 30-40%, then climbs back up to 65-70%. There's a pan of water in the room, and an oscillating fan blowing between the light and the plants. Does this all sound ok?

Light is 400w HPS ~20" away. It's dimmed to 250w at the moment. Do these plants look ready for the full 400 watts? I can increase the speed of the oscillating fan to provide more cooling to bring the temperature at the tops down. I'm waiting for delivery of a thermostat with a remote sensor which will control the exhaust fan, kicking in when the temperature at tops exceeds 75.

Opinions?

An update.

I vegged for 38 days, topping the plants once below the 3rd node in an attempt to get four main colas. This worked very well for three of the plants, while the fourth seems to have some other growth sites competing with the four main stems. I've considered trimming these back to give more room/light to the main stems, but I'm also interested in seeing what happens - a reduced yield for this plant might be worth it in the long run if I get a better idea of how different factors affect each plant.

During veg I transplanted them to 11 litre pots, then once more to 18 litre pots a week before flipping them to flower, as I was worried about them becoming rootbound.

They've been in flower for 6 days now, and they're all definitely showing female pre-flowers.

Pics 1+2 show the whole grow - the plants were about 18" when I flipped to 12/12, the biggest ones are over 22" now.

Pic 3 shows the four main growth sites of one of the plants.

Pic 4 is a close up of the mongo-mutant with its multiple growth sites.

Pic 5 is a profile view of the largest plant.



So how am I getting on?

What should I be doing in the next couple of weeks, do I need to start trimming and pruning?

And a picture of my electronics.

Main power is surge-protected at source, then into this five-way block which has a built-in energy meter so I can see how much the grow costs. Bottom of the picture is a timer for the amient heating, on during the day at the moment until the weather improves.
Next up is a fourgang which goes into the tent itself, powering the circulation fan and a tubular heater in the tent which is controlled by a thermostat.
Middle is a digital timer which has the intake and exhaust fans come on during the day cycle, and also for 3 minutes out of every 50 during the night cycle - I found this method to be ideal for keeping the temperature range to within a couple of degrees.
Top of the pic is the timer connected to the 400w Lumatek ballast. I've had some problems with this ballast, there's a faulty sensor which occasionally prevents the lights from coming on. A real pain in the ass, but the grow shop is replacing this as soon as another one comes in.

looks great!

An update, day 28 of flower.
Want to keep some pictures here as I'm definitely not leaving them on my camera!

Plants are now between 30-33", they doubled in size over the first three weeks of flower. Now there are crystals everywhere, and what look like big nugs forming. I really have no idea about this stage (or any stage I suppose), but it's getting pretty exciting!

Another photo dump. If someone could tell me how to rotate images I would greatly appreciate it.


34 days into flower.

The strain is supposed to have a 45-50 day flowering time. Am I right in thinking that I should leave it longer? Or at least that leaving it for one more week won't do any harm? They've had some mild stresses in flower (short periods of overly hot or cold temps).

Pistols look like they haven't receded yet. Its common to go over claimed time. Watch the trichs.

Thanks, I was definitely going to give them another two weeks, and I'm wondering about after that. how do they look for five weeks into flower?

They look good.

Another poor quality photo dump.

End of week six of flower.

Update:

Harvested 5.45 ounces dry. All curing in mason jars now. Aroma is sickly sweet, taste is fairly smooth, high is great!

this was a great thread, congrats man that was a very successful grow IMO! keep up the good work in later grows

Good job. What is the high like off the grapefruit? Have had my eye on that strain.

Ran a Cheese freebie from Dinafem and the plant was really good. High was a little speedy for me, but still a good high. Like a laid back buzz.

The high does what it says on the tin - a good blend of indica and sativa. There's a relaxing body stone and a good head high. Music and conversation benefit. It's not a good smoke right before bed, tends to keep me awake and bleary-eyed, but very content.