250W or 400W in my tent?

Well I've plumped for the 400w and it has arrived, along with all the sensors (temp, humidity, ph, moisture & light). Also SEEDS have arrived (AK47) so just waiting for tent and soil & nutes.

As far as ventilation goes I'm going to have to monitor as I go along and add what I need as and when.

Temperature in the loft is currently 9C/48F so basically the same as outside! Humidity about 60%

Maybe 4 is too many but I'll try and germ 4 and see what happens. This is my first grow so I'll be learning a lot as I go along. Once the kit is all here I'll maybe get some pictures up.

Thanks all for your input so far

signore said:

Well I've plumped for the 400w and it has arrived, along with all the sensors (temp, humidity, ph, moisture & light). Also SEEDS have arrived (AK47) so just waiting for tent and soil & nutes.

As far as ventilation goes I'm going to have to monitor as I go along and add what I need as and when.

Temperature in the loft is currently 9C/48F so basically the same as outside! Humidity about 60%

Maybe 4 is too many but I'll try and germ 4 and see what happens. This is my first grow so I'll be learning a lot as I go along. Once the kit is all here I'll maybe get some pictures up.

Thanks all for your input so far

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lol no maybes about it you aint gonna get 4 decent sized plants in that area, my mate uses a 1m x 1m x 2m tent and he barely manages to get 4 plants growing in that bitch lol

I clear 6-7oz in the same size tent with the 250W HPS. This is with 4 plants in the garden.

I'm not using a very cool source of air on intake, but if I was I would probably upgrade to a 400W setup. Even with the 250W I prefer to leave the tent open during daylight hours to keep temps as low as possible. Stick with the 250W and hopefully you are OK with 6-7oz at a time.

wbd said:

I clear 6-7oz in the same size tent with the 250W HPS. This is with 4 plants in the garden.

I'm not using a very cool source of air on intake, but if I was I would probably upgrade to a 400W setup. Even with the 250W I prefer to leave the tent open during daylight hours to keep temps as low as possible. Stick with the 250W and hopefully you are OK with 6-7oz at a time.

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Dude if I could pull 6-7oz I would be over the moon - I'm setting myself a modest target or 1oz per plant. This is my first grow so I could screw it up and get nothing!

My air intake is VERY cold air (currently sitting at 7C/44F and dipped to 5C/40F last night). With 400w in that tent I will probably be running with the tent open and a fan blowing in, just gently for some breeze. It will be trial and error to see the best way to stabilise the temps. My main concern at the moment is the temp dropping when the lamp is off, I will probably have to close up the tent to try and keep in whatever heat the lamp has generated so see my plants through the "night".

Anyway good news, everything has arrived and is ready to go. Got my soil, nutes and pots. Just have to run the power up into the attic and put the tent together, hang the light etc. Will start germinating tonight also.

I grow in a Secret Jardin Dr60. I use a 250 watt hps cool tube with a 6 inch inline hydrofarm ductfan attached. I ussually grow between 3 and 5 plants. I average an ounce to an ounce and a half per plant. I do not know what sort of tempertures you face year round but where I live the temps in the tent have proven to be a huge issue during flowering in the summer months. Temps can easily exceed 90 F. Good luck with the 400 I will be very interested in watching how it performs for you.

wheelt01 said:

I grow in a Secret Jardin Dr60. I use a 250 watt hps cool tube with a 6 inch inline hydrofarm ductfan attached. I ussually grow between 3 and 5 plants. I average an ounce to an ounce and a half per plant. I do not know what sort of tempertures you face year round but where I live the temps in the tent have proven to be a huge issue during flowering in the summer months. Temps can easily exceed 90 F. Good luck with the 400 I will be very interested in watching how it performs for you.

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Where I am, I'll be looking at average summer temps of anywhere between 10 and 20C (50-68F), high 20s is a really nice day, if it hits 30 (86F) that's a "scorcher"! I'm more worried about the overnight temps over the next couple of months as it can drop to anything between 0 and -10C (32-14F). not sure how I'm going to handle that, but I'm gonna have some fun finding out

signore said:

Dude if I could pull 6-7oz I would be over the moon - I'm setting myself a modest target or 1oz per plant. This is my first grow so I could screw it up and get nothing!

My air intake is VERY cold air (currently sitting at 7C/44F and dipped to 5C/40F last night). With 400w in that tent I will probably be running with the tent open and a fan blowing in, just gently for some breeze. It will be trial and error to see the best way to stabilise the temps. My main concern at the moment is the temp dropping when the lamp is off, I will probably have to close up the tent to try and keep in whatever heat the lamp has generated so see my plants through the "night".

Anyway good news, everything has arrived and is ready to go. Got my soil, nutes and pots. Just have to run the power up into the attic and put the tent together, hang the light etc. Will start germinating tonight also.

Click to expand...

Well if you picked up the 400W, you're probably going to exceed your expectations by quite a bit. 1.5-2 per plant should be easy enough for ya so long as the temps don't work against you. And of course you don't make any other major mistakes.

But even with a less than perfect grow you can probably bank on 6oz no problem (which is what I shoot for with my 250W, it's harder for me though!). Good luck!

I get 5 medium sized plants in my 1m by 1m. i could maybe get 6 in.

OK chaps, my grow is underway

Germinated four seeds using the paper towel method, all popped within 36 hours, then I put them into biodegradable seedling pots with BioBizz All Mix soil. They've been in the soil 5 days and all are standing at about 1 inch high, so all good.

My next challenge was getting the temps under control in the tent. My tent is 65 x 65 x 145cm (2'2" x 2'2" x 4'9") and I have a 400W dual spectrum HPS lamp. I was hoping to be able to get away without any active cooling but I soon realised that wasn't going to happen. With the light on and the tent closed up, temp soared to well over 110F. Even with the rear flap and the front door open, it was still over 100F, no good at all.

So I picked up 2 x 100mm (4") extractor fans (107cfm) and some ducting and set to work. At first I tried having one fan blowing in and one extracting but this only brought the temp down to about 90F. Then I tried having both fans extracting air, and opened the rear flap slightly to allow passive air intake and bingo, temp is now around 80F and there is a nice breeze flowing through so I may be able to get away with having no additional fans to move the air inside the tent

Here are my little ladies after 5 days in the soil. I am using plain water and watering in very small amounts (using a mister) when the moisture meter says they need it, which is about every other day at the moment.



Next question: When should I put these under the light? I have heard people say that you can put them straight under, even before they break ground, but also heard some say wait until they are 2-3 inches tall, or have a certain number of leaves. What does everyone think?

I guess I am a bit late! Well...anyway's

Biobizz all mix is a bit to early for such young plants, better would been light mix. As soon as you see the first leaves, put it under the lights, but not to close!!