Stretching plants? (with pics)

Ello there guys, well im about a week into sprouting and i've got a nice rootsystem poking out of the tip of my jiffy pellets, thing is, they're quite tall and stringy but they have nice foliage developing and as said, a pretty nice amount of roots poking out of the bottom onto (and some into) my clay pebbles, I have them on a 3 hour cycle for watering, flood for 2 minutes every 3 hours everyday.

my lighting cycle has for the past 5 days has been on 18/6 with a 400WHPS about 23 Inches away from my plants with an exhaust fan which cools the closet down alots (between 70-75 (more accurate reading)).

The question is, Are these heights normal at first growth or are they stretching quite a bit, baring in mind it's going to be VERY difficult lowering my light any more because of the light temperature.

Anyway guys, lemme know cuz i wanna know how my baby's doin they look healthy in my opinion...

Here's the pics,

Sensi Star x Skunk #1 (first planted)

Lowryder x Santa Maria (second planted 'my baby!')

Lowryder x Santa Maria (third planted 'my second baby...')

Apologies for the shitty camera and it's also under my inspection light, picking up a nice camera soon!

looks like stretching

Two things I can tell you your doing wrong.

1. Lighting! You should be using a florescent light for your seedling. Or even a Metal Halide. HPS is mostly in the red spectrum, of course depending on the bulb used. Red color spectrum is best used for the flowering stage. With a florescent light you can bring it closer to your plant and this will help prevent stretching.

2. Water! At this stage to much water can and will cause seedlings to grow funny. I would cut back to at least once a day. The clay will retain moisture for a better part of the day, but check a few times a day to see if clay is staying wet.

Take a look at the pic I included here. T-5 Florescent - I have about 3" above the light.

Click on pic. to see bigger pic.