Rookie mistakes. What to do about it?

Hi it's my first grow, not quite sure what things look like yet.

I have a 400w MH bulb on a 18/6 hour light cycle. I have a nice sized room and a fan going on them at all times. Temp is about 72 and RH is 52%. I haven't gotten anything to test PH levels.

I think in my noob-ness I got scared and overwatered them. Have not added water for almost a week, but soil is still very wet about 1 inch down. 3/5 plants are turning yellow from base and going up. Is this just typical overwatering? I tried 'airating' (poked holes with coat hanger) but moisture metre still goes off the chart.

Also, my plants are growing kinda slow. It's Week 6 and they are only about 6-10 inches high and have maybe 5 tiers of leaves so far. Is this normal? Or is this because they are overwatered?

How do I get the soil to dry out so I can get back on a regular watering schedule?

Welcome.. Maybe you could try to transplant them into a different pot to see if that helps or wait till they dry out on their own.

After week they are still wet 1 inch down ?
How big are the pots and what kind of soil are you using ?
Even a waterlogged 5 gallon bucket should be almost bone dry in a week...

I would repot and hence forth water by weight...buy a cheap scale...weigh the pot filled with soil ( dry )...add one pound a month for root and plant weight.

Never over water again.

Are there enough drainage holes ? Are they blocked with debris?

And yes the slow growth and yellowing of leaves is a sign of overwatering...

Thank you my dear ogre friend! I put rocks at the bottom but they were tiny rocks, and I think your debris theory may (much like my pots) hold water. If I repot, what soil should I use? I used the Miracle Grow vegetable soil. I was supposed to mix it with sand? Like playground sand? Fancy weed sand?

Where do you get a PH kit? I have dehumidifier on standby. 55%RH and 73 degrees as of midnight Friday. Top 1 inch is dry but below that it's all packed and wet. I am depressed and watching them turn yellower and curl up every day. My wife is very upset that I bought this huge lamp and now I'm screwing it up like this!

Oh well. How dangerous is a repot, anyway? How much of the old soil do I keep? Brush it away? Try to keep the "root ball" intact? I grew up in the suburbs, I have no idea what I'm doing.

http://www.grow-light.com/Pro-pH-Drops-Test-Kit_p_1526.html - at least get something simple.

MG soil is shite. Definitely try to get to a near by store if you can to pick up something a lil better. playground sand? wtf?

what grow nutrients are you feeding them? yellowing? bam. sounds like a nitrogen deficiency. its a foliage based WEED. its a nitrogen-phile if you will. they are starving. feed them.

They are probably starving because the overwatering has flushed out all the available nitrogen. I wonder if the time release nitrogen will begin to release more or if that has all been washed away.

I see. So is there a way to add nitrogen quickly and easily? I've already spent way more on this experiment than I thought I would. I thought this was a WEED, give it water and sunlight and BAM, right? Clearly that's not the case.

So repot in what type of soil? Brand/type would be best, and yes something I can buy at the local Home Depot. And where do I get nitrogen nutrients?

Thanks guys!