Water will eventually recycle and treat itself but in larger metro areas treatment is an added cost.

If the plant uses X gallons per day with DWC it will need X gallons with fogponics. It'll just be in a more gaseous state rather than liquid. I couldn't say it's inferior or superior, it's just another way to grow.

SisterMaryElephant wrote:Water will eventually recycle and treat itself but in larger metro areas treatment is an added cost.

If the plant uses X gallons per day with DWC it will need X gallons with fogponics. It'll just be in a more gaseous state rather than liquid. I couldn't say it's inferior or superior, it's just another way to grow.

Fogponics wouldn't be so good for me anyway because most peeps who journaled it grew many small plants as opposed to a few big ones. Since my exemption puts a limit on the number of plants but nothing else, I'll stick to the original RDWC plan.

Would make a nice cloner though!

I've begun construction of my 4x8 enclosure but I need to revisit my plan of getting multiple SS800. I've went through a lot of your post history here, and your opinion on the matter is quite clear: LED is still too expensive for what it produces.

I've never seen a 1000w HID in person, all I know is what I read: it draws about 1090w with ballast and generates a lot of heat, but watt for watt isn't it the same amount of BTU of heat generated anyway?

At 32sqt I'd ideally want 2000w at the very least, right? I'd originally planned to go with 4x SS800 for the simple reason they're convenient (veg/bloom switch), convenient to install (just plug it in) and already air cooled. With a big enough chiller it'd be a true plug and play grow.

Assuming I could break even after two harvests at most, would you still not recommend four SS800 over two 1000w HID? (If a SS800 is almost equivalent to a 600w HPS but not quite, I calculated that 4x SS800 would be about the same as two 1000w HID).

The biggest disadvantage is obviously the capital investment. The biggest con you often brought up against LED vs HID for the equivalent wattage is that LED lacks penetration. If I scrog and grow an even canopy to reduce the penetration disadvantage, would it not maximize the benefits of LED? I want to make sure I cover all the angles so my decision truly is informed.

The cost benefit analysis does favor 1000w HPS in most scenarios but there are times when 600w HPS or even LED can work well.

I've never used LED, myself, but many journals here say that the SS800w (620-ish watts) is about the same total heat output as a 600w HID.

Assuming 4x8 I'd run 2 x 1000w HPS if I were designing a HID solution. CLW says that their SS800w will cover a 4x4 area, in flower, but that's a bit light imho. 4 x SS800w would be a little excessive but you'd see decent results and have great coverage throughout the entire grow area. Just the number of lights to cover the same area begins to show why HID is so cost effective.

Cooling that much light (HID or LED) is another issue and there are multiple options, none of them cheap.

I'm not sure what the ROI would be, it might be several harvests depending on the complexity and quality of ALL of the equipment. 4 x SS800 lights would be about 2480 watts, which is about 20% more than 2 x 1000w HPS. The intensity/penetration would still favor the HID but you need less penetration if you're sure you'll be doing SCROG. 1000w HPS is a little overkill for SCROG but a lot of commercial growers use them so they don't have to buy as many 600w HPS lights. 600w HPS is good SCROG light but you'd want 4 of those too, if you wanted the best coverage and intensity.

So that's what *I'd* suggest, lighting wise, for a 4x8 SCROG:
4 x SS800w or 4 x 600w HPS or 2 x 1000w HPS

Does it have to be 4x8?

SisterMaryElephant wrote:Does it have to be 4x8?

No! I can configure it to what I desire since I'm building it custom. I've ordered enough orca film to cover twice as much space.

I was planning on installing two light rails with two SS800 on each (the lightrail5 supports up to 100 lbs and two SS800 weight 65 lbs) so the canopy would grow completely evenly.

As for the cooling, I'd copy my current watercooled AC system, but upgrade the cooling capacity as needed.

The Icebox 8" has a 8400 BTU cooling capacity, so if I use two of them with the appropriately sized chiller (in this case I would probably serialize two 1/2HP chillers in the loop) it would cool 4x SS800 without any problem whatsoever. I'd run CO2 inside, keep the enclosure sealed, with a DIY 8 sites RDWC + control bucket with float valve that I could place outside, with a bigger res attached to it for automatic top-offs. Add an automated nute drip to the control bucket, and I'd have one fully automated grow room.

You won't regret 2x 1000w HPS. Just my opinion.

I've heard rumors that plasma lighting is comparing well to HPS. Any thoughts guys?

beefxer wrote:You won't regret 2x 1000w HPS. Just my opinion.

I've heard rumors that plasma lighting is comparing well to HPS. Any thoughts guys?

I had a conversation with a botany grad student on campus last month about plasma lighting. He said the literature didn't support the claims made by the manufacturer yet. We didn't go into details because I had never heard of it. I had actually went to see him to discuss induction lighting.

beefxer wrote:You won't regret 2x 1000w HPS. Just my opinion.

The thing that turns me off about HPS is the need for reflectors, to change bulbs, to install the ballasts... it's a lot of extra equipment. To cool them properly I'd need an icebox 6" for each of them, which means more water manfiolds and a more complicated loop to setup. Heat management is easier too because the ambient temperatures in the room with LED is equal to the temperature above canopy, whereas with HID the canopy temps are usually 10F higher than ambient temps. I learned that when I researched SME's suggestion to push 90F with LED earlier in my journal.

Four SS800 would just be so much more simple. Hook them up to a the rail, plug them in, turn on the veg switch and all you have to do until harvest is flip the switch to bloom at the appropriate time. KISS.

Well, if you're not confined to 4x8 then you have more options.
2 x 1000w HPS in a 4x8
3 x SS800w LED (or 600w HPS) in 3x10 (or 4 in a 3x12)

I'd still skip the light movers, if you have that much light you won't gain much, if any, by using them.

I might change the "bucket" design when you ramp up but the RDWC idea still has merit...

If you're thinking about adding dosers take a look at the SGSensors products.

SisterMaryElephant wrote:
I'd still skip the light movers, if you have that much light you won't gain much, if any, by using them.

There really is no gain to a canopy growing evenly? I'm gonna e-mail Ed Rosenthal about his claim in his book that even if the light only moves a foot in either direction, the boosts in yield is still significant. Nobody will answer probably, but it's a pretty bold claim to make for a book that is otherwise heavily anchored in empirical data. He suggested a 10-20% increase in yield. That's huge.

What do you mean about the bucket change?

I just measured and 3x12 would actually fit perfectly! If you say lightrails wont change anything, then that's already a big saving then.