First time indoor, need some help for the set up

Hello, I am about to start an indoor culture and since it's the first time I'd like to know if I'm doing well.
So, I have a 5x5x7 grow box (1.5mx1.5mx2m). Then I have a carbon filter, an air intake kit, two 600 W HPS lights, and a small fan. I'm going to use soil, root fertilizer for the first three weeks, and then some standard fertilizer from week 5 onward. I'm pretty sure I'm going to use "Gelato" seeds, which i heard have a great taste, an amazing smell and a very large yield.
All my seeds are going to be feminized.
I was thinking of having 30 plants inside the growbox.
Now, my questions are:
1- are 30 plants too many for the space i will use? I've often heard that when growing indoor you should focus on having a lot of smaller plants over a small number of them, but taller. But how true is that?
2- is the light setting enough for 30 plants? I was thinking of adding some smaller hps light, like a couple of 100w.
3- is one small fan not going to be enough to cool the temperature? How many will I need?
4- At what kind of yield am I going to look after, say, 6 weeks of vegetative and 10 weeks of flowering?

Thanks in advantage for your answers

30 plants will work in a 5x5 if you run from clone with very little or no veg time, Otherwise welcome to the jungle. 30 plants from seed , good luck

2x600w hps should be fine in a 5x5 I think. Most are using 1 x 600 hps in a 4x4

1 small fan won't be enough for air circulation, fans don't help raise or drop temps, they just move air around. You will need a fresh air intake brining in cooler fresh air or ac

1 pound fo sho


Take my answers with a grain of salt, I'm still new myself, but I've done a lot of reading and Adkin questions since starting
Best of luck with it

Yeah unless you're going to grow a SoG type setup, 30 will be far too many. You do have a pretty good amount of light for your setup though, just monitor temps. While small fans won't drastically affect temps, they certainly do help to drop a degree or two when placed to move the air between the canopy and the light. I have a very similar sized grow space and I use a big 16 inch oscilating lasko fan and it works perfectly. It works both for moving air between the canopy and the grow light as well as to make the plants 'wave' and 'flicker' which you want in their early growth to help thicken up their stems for later blooming. So I'd definitely consider a larger oscilating fan, in combination with one or two small desk fans constantly blowing over the canopy while the big fan is osciliating back and forth across your plants. Light won't be what limits your number of plants, space will be. 1200w HPS altogether will be plenty enough for a 5x5 grow space. It is very hard to tell what your yield will be just because of strains and other dependant factors, but with 1200w HPS I'd be shocked if you yielded anything under 1-2lbs. But that's a very general estimation, once you find your strains I could give a more accurate guess. Hope I could help, plz keep us updated with further questions
*EDIT* Forgot to mention, there is no set standard to having more over less plants indoors. You can still grow fewer monstrous plants or lots of small plants (SoG). Personally, I try to find the sweet spot in the middle. I feel like the middleground is the most efficient in regards to yield.

Thanks to both!
So, what I need for ventilation is just another pair of small fans, and if that's not enough I'll put another bigger one. Got it.
About the temperature,the ventilation kit is going to do most of the cooling, right?
I've read something about the sea of green technique, it sounds very interesting!