[color="#800080"]Hi,

I have just bashed a growdrobe together (6' high, 6' wide, 2.6' deep), 424 tank, 200w enviro (for my 2-3 weeks veg), and an old skool 400w sodium growlight (the kind that has the ballast and shade all in one unit and heavy as hell!!).

Anyway, being a bit of a newbie, and friends all having conflicting views (tut and sigh), i'd appreciate a bit of help.

1. I understand the ph needs to be about 1.2, wondering if this includes the ph of the water or not?

2. What is the best temp for the water in the tank?

3. Is it ok to use the 400w sodium bulb for my grow in my growdrobe without buring it down! I have a 12" fan which i intend to put in the room, but as yet only have a simple electric extractor 100mm lodged into the side of the hardboard.
I know a good extractor fan is needed as with a bit of angled ducting, but thats not affordable till the first grow is done.
Will the loss of light through the extractor fan make much difference?

Well, thats about it (for now!), thanks in advance for all your help.

I'm still trying to figure out the science of it all, like whats the diff between ec meter and ph meter, and is it the nutrients that affect the ph or the ec?

I know it's not rocket science, but knowledge is power and i can say, hand on heart, that i'm a bit wet behind the ears with all this hydroponic malarkey.

But... i am keen as mustard to learn and no better place than this forum, rather than the many 'pub' experts who have shared their totally different wisdoms!

many thanks, chris.

look at peoples hydro grows on web site, all the answers are at your finger tips mate, have you read up on hydro yet?

U wont be able to use a 400W HPS with no extraction or inlet u'll be way to hot mate. PH should be at bout 6 ish

Water temp not to sure i would say 70 ish but i dont no so wait or look for the answer loads of hydro grows on here to look at best way to learn is read ALOT on here.

Hi Pilgrim. Good to see how keen you are, but you need to do some more reading mate. First off, Evans is quite right, you'll never control the heat in a drobe without a proper extraction fan. You can't bodge this part I'm afraid, you have to spend the money. And you also need the proper fan because you absolutely MUST get a carbon filter, and only a proper fan will be able to pull air through it. Growing cannabis makes an unbelievable stink, without a filter you'll get busted in no time.

I'm not a hydro expert at all, but there are two key readings, EC and pH. pH is a measure of how acid or alkaline the water is, EC is a measure of how much nutrient has been added (loosely speaking), and has to be gradually increased over the course of the grow. The hydro experts are unanimous that you must buy meters to measure both, which are quite expensive I'm afraid. It wouldn't be 1.2 pH, that would be so acid it would probably dissolve the drobe!

I think that he was mixing up pH and EC in his FP.

Pilgrim, have a read of this. NB, ignore the bit about using citric acid instead of pH down, it's now considered not stable enough.

To you all, many thanks. I can wait to get them vegging!

Now i'm off to read tons of stuff from this forum!