I live in an extremely dry valley client; I'm watering once a day at this point. Is it pretty safe to do this assuming the soil is dry?
If the soil is drying, yes it is safe.
Of course, if you're flushing the soil regularly, you'll want to make sure to maintain adequate
I often stick a dowel or kabob skewer deep into the pot to tell me when the lower layers of soil
are actually dry.
I'm still using 4"(?) Jiffy pots, as my seedlings are a little behind, so I can generally tell at this point by lifting it up. I use a fan to circulate air in my mini tent, so I'm guessing that's the reason for the swift evaporation; if I don't have it blowing while all 5 45w CFLs and the T5 is cranking along, it gets really stuffy in there.
In 4-inch pots, you might have to water multiple times per day ;-)