[Puffer Pita]

I don't know about mixing species but I wouldn't get more than 1 more in a 10g tank. They do get territorial and are very vulnerable when they've molted.

The best way to acclimate anything from freshwater to brackish (or SW or vice versa) is by drip acclimation. This explains it pretty well (don't do the float method, that is for adjusting freshwater to freshwater and saltwater to saltwater): http://www.liveaquaria.com/general/g...3319&subref=AI

Guestimating a CPU's core temp is one thing but guestimating water parameters is something completely different. You definitely need a test kit. I highly recommend Aquarium Pharmaceuticals Freshwater Master Test Kit. It has all of the basics and will last a good long time.

Keep up with the daily water changes, even if you have the salinity where you want it, until the cycle completes. You'll need the test kit to know for sure when that is - when the ammonia and nitrites read zero and there are some nitrates. Then you can back off to doing water changes and gravel cleaning once a week. Don't clean the gravel during the cycling process though.

Not sure what water conditioner you are using but I highly recommend Prime, especially during a cycle. It will detoxify the ammonia and nitrites, making them less poisonous to the livestock but will leave them available for the cycle. Its also safe in overdose amounts.