How many under 400 watt?

I want to do a 2 liter bottle sog grow under a 400 watt hps. I have a big closet to do this in so I think I can get about 16 plants under it. Does that sound about right? What do you think would be the max amount of plants you could get under it?

I use a 400 for flowering and yeah you could probably fit 16 2 liter bottles under there SOG style, might get kinda cramped; but it could work if you kept the plants small....make sure you cover up the bottles so light doesnt hit the roots, lights and roots are a bad mixture.