Complete newbie question, my plants are currently 5 days old from seedlings. Just today I've replanted them into slightly larger pots from very small cups. See photo below of plants today: View attachment 136694 Am just wondering when I can put them under a 400w HPS light? I've currently got them under a very low powered LED lamp. How close should the HPS light to the plants? Any help I'd be most greatful.
Ok light set to 20", I'll see how they go. I've still got to get a thermometer, once light warms up tent should be pretty toasty. What sort of temps do I want to aim for? bearing in mind I am uk based. View attachment 136695 \t
Somewhere between 20-25C with the light on is a good temp. 29C is the max temp you would want. At the same time, when the light shuts off, you want to be sure the temp doesn't drop below roughly 15C. I recommend buying a thermometer that also has a humidity reading. They should sell cheap ones at the local hardware store. Do you have any ventilation and/or fans running inside your tent?
No fans at the moment, getting a clip on one this coming week which should do the job. Will have to look into the temps, does't help the tent is located in the coldest room of the house. Should the fan be angled over the plants or what?
Actually, it may help that you do have them in the coldest room in the house. You do not want to bake them under your light. I wouldn't be overly concerned with only a 400W lamp, but it's easier to add a bit of heat than take it away. Do you plan on installing ventilation to bring new air into the tent, or adding CO2?
Not really thought about ventilation/new air inside the tent, these plants were going to be grown in cupboard but got hold of nice grow tent today. What is my cheapest option for ventilation/new air in the tent?
Only plus side is tent is right next to house air vent which I could easily attached some sort of duct going into the tent.
A large computer fan might be your cheapest option. I'm not sure what craigslist is like in your area but you could check the farm/garden section there to see what used fans you might find. Something 4-6" for exhaust might work good for your space, and you will want a filtered intake just slightly smaller than the powered exhaust. My room is a larger scale than your tent, but the same principles apply. If you want to check out what I'm doing, look here http://forum.grasscity.com/indoor-grow-journals/1292225-first-grow-2x-1000w-mh-early-stages-working-out-quirkes.html
Ok I have computers and fans I can take out and use, but what's the best way to power the fans from the computer? Will check your room out.
Just going back to my 400w lights, I've had them on for just over an hour and one of my seedlings have just flopped over. Do you think my lights are too close or too hot for plants?
I'm growing in the UK mate, so i can give you a hand with temps as there basically the same i'm experiencing as were heading into summer now. You will absolutely need an extractor fan and if it's not to air tight in there you could make use of negative pressure as intake and the fans need to be moving air in the grow room but not blowing directly on the plants for seedlings just placing the fan above them on a wall or oscolating somewhere it's not obviously to windy for them. A 400w is a lot of light and heat as i use HPS as well and started out without ventilation and i can tell you now like £65 later after getting a great extractor fan, ducting and a carbon filter it's essential..
That sucks. It sounds like it might be too hot. Monitoring your temp (and humidity) are pretty important. Maybe raise the light up just a bit and get something to check the temp asap. I do not want to be responsible for killing your plants. lol As for powering computer fans, you need to know what you're doing somewhat. I think you can either modify a computer power supply or find a 12V ac adapter.
that's not enough, you can use them for intake and you'll need 2 + depending on the size of your area and you'll still need an extractor fan, as said above you can wire them into a 12 volt ac adapter. Also 20" would probably be fine in most setups but as of now you don't even have a fan of any kind you want them to be a bit higher than that, raise the lights depending on the temp, what i'd do is check the temp now, if it's above 27c i'll raise the light, the only thing you can really do when your not controlling the eviorment is to just get them as low as you can but no hotter than 27c 28c ideally. Leave the door cracked open if you haven't already, there not as sensitive to light leaks at this stage, stale air's what you don't want
I will have fan and thermometer by tomorrow. Yep can see how quick the tent heats up from just using the light for a few hours, I think your right may have to splash cash and get extractor asap. My tent is only 60cm x 60cm x 200cm, but has all the vents for the ventilation etc. May drop you msg laters.
Those are the measurements of your tent i'd get those lights up , you'll be fine it's probably mylar reflecting, it'll be enough for seedlings and 400w is quite a lot which is also thermal instillation keeps the heat in, it's great but only works well with ventilation and still adds like 3c 5c in my experience. Feel free to pm me if you need, this is basically the kit i got. http://www.ebay.co.uk/itm/4-Premium-Hydroponic-Grow-Room-Carbon-Filter-Fan-Ducting-Kit-250-m3-hour-/110886558037?pt=UK_Home_Garden_Hearing_Cooling_Air&hash=item19d15a9955 You might be able to get a slightly smaller cheaper version that'd do the job because my closets quite a bit bigger than yours and it works great with my setup.