How do you know when to switch from solo to pool?
Difficult to judge. Around level difficulty 1 with my 900mhash it's usually more profitable with a lot of coins, but once it creeps past 1.5 it becomes quite slow, and because the chance of finding a block decreases quite a bit, you may go 6 or 7 hours without finding a coin, and that's when it's time to hit a pool. At least you're guaranteed a steady payout that way.
Usually for me I will solo mine a coin I think is worth holding when I find a block roughly every 3 or 4 hours. Once it creeps past 6 hours, I usually go to pool mining.
At the rate the hashrate is currently increasing, by tomorrow I'll have to switch to pool mining. Going to see if I can mine a few more blocks overnight. I'd really like to hit 5k before having to switch to pool mining.
Less money but good news l
Coin Army has a 25Mh rig parked on it
That does worry me a bit. Someone holding that many coins.