Growdobe Needs help

Hello all. I am building up a setup in a wardobe closet. Only problem is im worried about hanging my 400w and my carbon filter and inline fan and cause the thing to tip over with all the weight up top. What do you think i should do as far as to anchor it? I cant find a stud in the wall to anchor it too. Should i put some bricks in the bottom of it so its heavy? any ideas?

This is the back of it and the wall

any ideas?

i'd say anchor it to the wall or the bricks, they're both seem fine

Can you anchor just into drywall? Im a new home noob here lol.

you could if you can't find a stud?

Yea i knocked on the wall its around to find a stud but dont hear any diff. Other way to find a stud maybe?