I thought and did the SAME exact thing. Only I germinated 27 seeds and now have 26 seedlings to tend with. Oops?

In my case; I don't have any grower friends to gift them to or really any other way to deal with them other than trying to grow them. I wouldn't sacrifice them and not grow them though; that'd be pretty wasteful unless you didn't spend any money on them. You could sit there all day (like I did) and say "Shouldn't have done that.... shouldn't have done that!" but at the end of the day, you did, and now we have to learn to deal!
Here are some ideas I thought of:
- Know a friend or other grower that could take them? Gift 'em out if you feel charitable or slap a "rehoming" fee on 'em.
- Money tight? Can you afford another bulb or tent to stick the extras in? I have two 125W rated CFL's that I use for my seedlings; I've contemplated myself using that box to grow one or two plants in under those lights to ease the burden.
- Try smaller pots. That's what I'm going to do on some of my strains. I'm going to pick the strains that I want to be the biggest and most bad and give them the gallon sizes most appropriate. The other strains that I'm more "ho-hum" about are getting smaller pots. The advantage (at least for me) is that I can fit more of the plants under my lights; albeit at the loss of massive growth and more bud weight; but that's a happy median for me instead of throwing them out. I'm also contemplating planting a few in a plastic tub (you can get 14 gallon plastic tubs at walmart for $5.) If you are worried about root contention; you can take cardboard sheets and make a "grid" in the tub, effectively dividing up the spaces so that roots won't easily be able to infiltrate the space right next to it. I have a 17 gallon tub I've been eyeballing at home here; and I could easily fit 8 plants in it at more than 2 gallons per plant. You will have to LST them though or you're gonna have a tub of bush. Which leads me to the next idea:
- Low Stress Train the crap out of them. Try to get the foliage to lean more predominately on one side (closest to the light,) especially on the plants that are in the outer "ring" of your light.
I've read a 400W light should be able to cover a 3x3 area very well and a 1000W light will cover a 4x4 area very well. Since you are running about 600W, I would think you'd be pretty close to having enough light per plant (if you reasoned 1 plant per 1 square foot); but it looks like in your picture the two pots on the far left side of the photo aren't getting much light. That's the issue I've found too with rectangular tent; that square footage gets wonky when the tent isn't square.
Anyways, that's just my two cents. I'm a newbie grower myself; so feel free to take my advice with a grain of salt; and I'm sure some more veteran growers on here will help advise and/or correct any mistakes in my suggestions and offer their own. Good luck brother; and here's to both of us underestimating our incredible prowess in germination!