Temp. and humidity problems

I have a 400w MH on 8 seedlings right now, about 2' away from the plants. My problem is with my temps and humidity. The Temps. reach up to 88F during daytime and all the way down to 60F in the dark. Im pretty sure that temperature shift like this are not healthy, although my small plants look good, i would like to nip it befor it causes problems down the road.

I will be making a cooltube tomoro, and getting a inline fan to get it all going. For intake i use 4 homeade light baffles (4"x4") in the side of the gro cab, but im not sure it intakes air well enough, does anybody have any advice on how to add air intake. ie - DIY, intake products etc. etc.

The humidity is down around 20% all day long, how can i raise the moisture in my room to get my cab around 35%??

Pic 1 - Garden.
Pic 2 - Baffles from outside.
Pic 3 - Baffles fro inside.

Thanks for any advice in advance.

I think the temp shouldn't be much of a problem. Maybe if you have a fan that's going on in the dark time just turn it to a lower speed. To raise the humidity you can put a water bucket, a damp towel, a humidifier or get a mini fogger/mist maker for the room :P The humidifier might be better as you can put it in the room and not have people asking u about it.

Awsome, thanks mowie. im going to go get a small inline tomoro for my cooltube i made today, i may have to look for a humidifier. :thumbsup: