1st grow! advice appreciated

Have a 2.8x3.2 or 9 suare foot room, three sides have mylar and the other a white curtain, i leave the curtain open during the day and closed at night keeping the room b/t 66-76 degrees. Using a 400w HPS w. a mh conversion bulb at the moment with seedlings under the lights 24/7, grow is going well as of yet...any suggestions, a CO2 system or intake/outake fan may be needed, as of yet I believe i can get away without them...hoping not to have to purchase more but is intake/outake necessary w/ my temps. I use a 20in. stationary fan during the day and a 9in. stationary at night...should i upgrade or not...i really don't have the cash...hopefully i can get some pics for every1

Post some pics, but if your temps are that low with the light on(hoping you mean 66-76f) you should be okay, like I said drop some pictures and a better understanding of your system can be learned.

borrowed this pic from blazin...but practically the exact setup...got my lights a lil higher but then again blazin has an intake fan...hope this pic helps....have 3 surfaces like shown with a curtain in the front that stays open, 20in. stationary fan on the floor to lower temps when needed...but the temp at the level of the seedlings are consistently between 66-74, temp is between 68-78 at about 14in. from the ground...room has never went over 78 degrees F...thanks again in advance

here are some pics of the setup, let me know how everything is going, temp at base of pots ranges b/t 68-74 degrees F...light is 24in. above the top of the large pots about 27in from the small...big guy is a skunk #1 from a freebie pack i started awhile ago and will go outside when whether breaks...new to the indoor scene so help me out! pleez

one more

btw, the big guy is skunk #1, the others are some durban/skunk crosses by sam the skunkman, Lunas' Ak97 and NLX...first grow so we'll see how these strains will do and which turn out best:)

hey all, in the pics above u can see the one's in the small pots are thriving, for some reason my other seedlings in the bigger containers have shown veryl little growth, i'm 24in. from the seedling w. a 400watt MH conversion, should i move it closer

starting to take off slowly

well i started 12/12 a few days ago and everything has been going well, i'm extremely pleased so far since this is my first grow and haven't had any major problems...get some pics soon so every1 can check em out

o btw...that skunk #1 (big plant) is 3 weeks into budding and has a great scent and appearance...thick, compact...can't wait to try it out...patiently waiting :D

pics from today...i've been having some problems lately with very pale green/yellow leaves...i believe its a ph problem because its similar to the problem i had during veg...added some water with ph of 7.5 (bout 2 hrs ago) to hopefully buffer the soil...i had a very very similar probleming in the middle of my veg cycle so i think its ph...any ideas or diagnostics would help...i use cal-mag, liquid karma and biobizz biobloom...every two weeks with the first feeding about 4 days ago which made problem worse...nutes have ph of 5.8...only thing i can think of is that the 3 plants with problems needed bushmaster twice a week for the last two wks. in order to limit stretching...any suggestions