I purchased mine from Singapore. It came pretty quickly considering it had to come through customs. I've also heard about some people using dried Oak leaves and drift wood to add Tannins to water. Drift wood would look kind of wierd in my tank because of the decore I picked and my complex uses pesticides on the grass.
So mail order IAL leaves were my only option because of where I lived. I think other members who actually live near oak trees can give better advice on finding the right type of dried leaf. I brought mine from a professional to be o nthe safe side. There are a lot of sellers on ebay. The leaves I have are the C+ grade
. I think the highest grade possible is A+, but I'm satisfied with my C+ leaves. It's not like they have to make it into Harvard. XD
Nah, it's not neccessary. Drastic differences in water quality/condition is the reason for acclimation. :D As long as the acclimation is slow, the fish shouldn't be shocked. I can write out what I do below, but it involves using a fish bag instead of a floating cup. It also takes a while because I only use it when I've just brought a new fish home from a pet store. If I'm doing a large water change for an established tank, then I don't bother repeating. I seriously doubt salted water versus unsalted water could be a more drastic change than Petco water versus my tank water. :)
I use fish bags because I can hold a total of 2 cups of water. At first, I only fill it with 1/2 cup and float the bag and fish in my tank. After 10 minutes, I add about 1oz of water. Then I add another 1oz every 5 minutes until I get to about a 1 cups. I take out 1/2 cup from the bag, dump the water in a waste water bucket, and then repeat acclimation one more time. After it is 1 cup again, I just dump the bag into the tank.
Total time is about 1 hour 30 minutes. It's a bit excessive, but it insures the transfer is gradual. :)