i know youre supposed to use flat white paint instead, will primer work,like 2 coats or should i go out and buy a gallon of paint instead

Primer does not seal the walls all it does is gives a surface for the paint to stick to, it is the paint that seals the walls. Now say you spray your plants and get some on the wall and you only primered them, the water will absorbe into the wall and you more than likly will get mold and bacteria growing in your grow room. So paint the walls to seal them and to ease in cleaning up any mess you might make.

If your gonna use paint as mentioned above mold & mildew are problems that will come up,to avoid any mold or mildew on painted walls just buy a pack & mold/mildewcide paint additive when you buy the paint & mix it in with the paint,it only costs like $2 & mold will never grow on that surface.

OH,as said primer will not work for the finish coat,use low sheen semi gloss,flat is not very durable unless you seal it.

B & W poly works good too. It's the stuff thats white on one side
and black on the other. Just my $.02

__________________
Thanks for playing along! We all know I'm full of shit and have a great imagination...