First DIY Grow Box - Looking for Pointers

Hey there - I posted this in the Absolute Beginners thread and it wasn't getting much feedback, and then I realized it was probably much more appropriate for this forum.

I'm going to be trying my hand at growing for the very first time. I'm starting small, with just two clones - both DJ Short genetics - one Flo and one Blueberry. There's a reputable collective here in LA that sells clones of both that are clones of DJ's Mother plants. I get to pick them up next week!

I love building stuff, so I decided to go as DIY as possible through this whole process. My basic plan is to start the clones in a Rubbermaid box where hopefully they can stay through the vegetation phase. While they are Vegging, I'll begin work on a larger box that will ultimately be able to grow four full-sized plants through flowering, and of course there will be a curing room, etc.

So, after scouring the forums here for quite a while, I drew up a some diagrams for a Rubbermaid box design.



Okay, so this is all on the inside/back wall of the tote. I've already purchased the exhaust "system cooler" fan for a whopping $2.95 at a local electronics shop and rewired it to a 12V DC adapter. Works swell. Now I just have to do everything else.

I'm going to coat the whole inside with reflective mylar. Each of the Air Inlet holes will be 3" and the Exhaust Out hole will be standard 4" duct. All of the holes are going to be covered on the outside with a mesh fan screen to help avoid insects, etc.

I have two questions about this part of the box so far.

1) Am I letting in too much air? Can you let in too much air?? I read in the very useful Ventilation FAQ that you should be be replacing the air in the box every 5 minutes. Well, the exhaust fan I got is supposedly 30cfm and the box is going to be a total of ~12cfm, so it seems like if anything I might possibly need to slow down the ventilation, but I couldn't really figure out why having more airflow would be a bad thing.

2) I'm still undecided on the fan. I wanted to have a fan in the box because I was afraid that having the Exhaust fan and the Intake holes on the same side of the box would just cause the air to be sucked right in and passed right out without ever even passing over the plants. It seemed to me that even a small computer fan pointing away from that back wall in the direction of the plants could help counteract this. Though I also saw some people have used a small oscillating fan which might be even better.

Any feedback you could give me about these ventilation things would be really helpful.

Then there's the lighting...



I saw several people using similar designs and I thought it made great sense for a cheap/effective solution. So, it's just a 4" strip of 1/8" plywood, bolted through the top of the container, and I'll attach the power strip just using the standard wall mount hangers on the back.

I'll be using 26w 6500K Daylight CFLs, as recommended by almost everyone. My plan for the two clones is to have have a total of 4 of these bulbs, for the equivalent of 400w. And at least for these first two clones, I am planning to keep the lights fixed to the lid and to use spacers of some kind to raise the plant closer to the lights at first, then gradually I'll remove spacers as the plants grow. I'll also be doing all watering/feeding manually.

What do you think? I feel like overall it's a pretty basic design, but I'm also afraid I might be overlooking something major.

Okay, thanks so much for taking the time to check this out. I'm really excited about this project and I'm looking forward to posting about my growing adventures and learning about all of yours.

J