Need Some Help Please! First Grow!

Ok, I have a Secret Jardin DR60, 400 watt HPS/MH, digital ballast, 6" air-cooled reflector, 4" vortex fan, carbon scrubber, 6x4 reducer, aluminum ducting and a small oscillating fan. I have all meters, timers, etc.

Can I use the cool tube for the MH bulb as well?

I plan on using promix HP as a growing medium, with technaflora nutes later on.
Will this set up work for 2-3 plants? I have G13 Pineapple Express and Nirvana Papaya seeds.

Also, I have an ensuite bathroom I never use, and there's a big, glass, walk in shower. Could I put the DR in there? I already measured so I know it will fit, but i wanted to be sure the plants will be OK.
Any tips or suggestions are GREATLY appreciated!!

why the hell couldn't you?

I don't know, that's why I was asking?
Sorry for the stupid question, but disregarding that, does my set-up look OK?

dont need to worry bout gettin help on here this site is mint.everyone help if u ask right questions set up looks good im on my first grow did 28 days veg and its into 1 week of flowering read this thread and let us know what u think..ave u any pics...

Thanks Kevin! I'll take a look at your grow. I don't have pics yet, I wanted to wait till everything is all set up

be quick deffo following this lol...

Sounds like you have all the bits and pieces, pics are always a huge help and hope to see some soon.
feel free to ask any questions
I'll be subbed

Here's my first "real" grow, it has about a month until harvest
https://www.rollitup.org/indoor-growing/412407-1000w-jillybean-scrog-budget.html