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bEelzeBosS said:
Have another question for phychotron or anyone else that knows the answer.

During the last couple weeks of flower I switch to RO water only to get rid of all the nutrients, then I do an RO flush the day before harvest. For the last two weeks is it ok to water with just pure RO water that has a neutral ph or do I still need to bring the ph down to around 5.9 or so like I do when feeding?

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Your fine doing it the way you have been doing it. The ph thing is for nutrient intake. With the amount of time you're flushing for there isn't time to show nutrient deficiencies.

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phychotron said:
I just run tap water through it. Canna Nutrients are very forgiving and don't leave much residue. I have it set up to be able to run a ton of water through.

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GoonerHeClips said:

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phychotron said:
I just run tap water through it. Canna Nutrients are very forgiving and don't leave much residue. I have it set up to be able to run a ton of water through.

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Do you use Canna Boost in flowering?  If so, recommended amount?

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captain.koons said:
LEDs must run much much cooler than HPS. So at the very least they would be easier to manage with an AC vs. HPS. I didn't mean, no exhaust or AC at all.

Tent would have co2 on a controller ideally speaking, AC would be used to maintain temps and exhaust outside, and you would need a fresh air exchange however often ie. mostly sealed/perfect environment. I have a friend with a low tech co2 setup in his tent, he just has a regulator to pour disperse x amount of co2/hour and he figured out what the average ppms would be given his exhaust, room size, and air turbulence based on whatever manufacturer guidelines. I don't know how accurate that is but he's happy with the results. He also works for a place that distributes dry ice and tanks full of various gases so he just fills up for free.

4kw of light for most people = 250-350 cfm per 1kw in my case i'd probably be using two x 8" can fans = 500w and worse case for the AC would be 1100w so 5600w total probably have a small fan to exhaust the volume of the room twice a day or whatever is recommended. 5.6 kw /hr * 60days*12hours*$0.2=$806.40 in electricity alone under full ac/fan load. Whatever LED amount I found to cover say 1600 watt vs 4000 for "equivalent yields" (Granted this costs $7200 or would have from LEDgirl, then I'd just need to figure out the best/cheapest method of cooling I have no idea how it would compare. If I saved half of the electricity costs, I'd pay the LEDs off by electricity savings in just under 3 years! I still don't know how I feel about LEDs. In that time i'd probably also spend around $1500-2000 on bulbs alone.

What's the best priced / performance LEDs on the market?

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captain.koons said:
Is there a standardized equivalent?

I'd probably, as it stands, get 600-800w in a 4x4 to see the growth potential.

Have you heard of Apollo? Very good reviews on amazon. They also seem pretty cheap on amazon, I can also get 50% amazon gift cards.

http://www.apollohorticulture.com/cob-768w.html#prettyPhoto

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So I would put two XTE400's in a 4x4 tent and say that your pretty much maxed out on light potential. You could probably push it and do some crazy side lighting scheme to really get deep, but for the most part those ~740w will deliver as much light as you'd need. I'd love to see a side by side of two XTE400's vs a 1000w HPS. A friend has a 1000w in a 4x4 and its really pushing it on heat, in fact he can't start anything until he's solved that problem. We ran the bulb for less than 5 minutes and it was insanely hot in there.

The thing with LED's is that you want to spread the lights out as much as possible, so that one apollo for say a 4x4 area is not anywhere near ideal. Those 'COB' styles seem to be getting popular but I'm still not sold on them. I wouldn't get a light off amazon, they seem to only pass on generics or lower end stuff. Not saying you can't find one or the light is good, but its not the style I like. Its good to get it from a vendor who is developing the lights to grow bud, not just a "plant grow light."


Here's the light canopy for those plants above-- spread out to reduce shading from a single-point source. In my 4x8 I'm running 1270w utilizing a 4x6 grow area with a little overhang.



Also, because your running less wasted light, you end up running your garden a bit warmer as well.

I've derailed too many threads talking about LED's... Start a new thread if you want to talk about LED's.