[Rabiez]

Originally Posted by emeraldchild

While I was changing soil etc, I changed my Envirolite125 to 400 HPS. Very bright and hot.
Got to sort out venting. Got to leave door open to keep temps down.
Might be a good idea to change back to Envirolite 125 until venting is sorted.

I was going to say that the envirolite would be a better bet for a few weeks yet. However, your comment caused me to check back to your details on the bulb. You have a 2700K bulb, which is recommended for flowering, but for vegging you should be looking for around 6500K. Likewise, HPS is much better suited to flowering, rather than vegging.

Given this, I'd probably stick with the envirolite for now.
If venting is currently a problem, the envirolite will produce less heat. Also, the HPS will have to be kept well above small seedlings, negating some of the extra lumens it produces over the envirolite.
It's waay harder to screw things up with a flouro.

If it was me, I'd nip out and buy a 6500K envirolite, or a MH conversion bulb for the HPS, but I realise you'll have invested a fair bit in lighting already.

I'm not happy with the tower fan. Getting a desk fan tonight from my better half which is helping me out with the £'s, on a promise of testing first batch.

Stupid techno-fans!

Got my new digi HP. 1 pot is 7.5 and the other is 6.8.
STill using tap water which is about 7.5.
What should be the correct HP levels???

Heh, it's pH, and you should be aiming for around 6.5 as a first timer. Anywhere between 6.2 and 6.8 will keep the plant happy. Be sure to test and adjust your water before watering, and also test the runoff from the pots. Any significant variations will need addressing.

Venting - above cupboard door is kind of like a blocked window with boarding. Thought I would use this to make a hole and run tubin into grow area.
Might make two, one clean air going in and stale air going out with carbon filter.

There's a few things worth considering when it comes to venting.
Firstly, I'm in complete agreement with Rumpleforeskin; ovekill your ventilation.

That said, I'll move on. The setup you propose will work to cool the grow to an extent. You'll probably need to crack a window open to provide CO² to the intake, and cool the room once the HPS goes in.

Noting that you might make 2 holes, I'm gonna have to tote a sticky at ya. Have you read the Grow box design guide, and searched the Grow Room Design/Setup forum?

There that's only 3 paragraphs, so I didn't go off on one at all. Ha! I'm proud of myself.