Using Ice for Wort Cooling

I'm interested in getting some opinions on using ice to cool hot wort.

I brewed a couple of weeks ago and put 2 gallons of cold tap water in my primary fermenter and added the hot wort and topped it off with cold water. The thing was still very warm to the touch. So much so in fact that I had to cover it and leave it to cool off overnight. I've never had this problem before.

Is it okay to put some ice in the two gallons of tap water I add to the primary before I add the hot wort? The ice comes from the same water supply as the tap. I've read the ice should be sterilized, but that's not really an option. My fridge's icemaker does filter the water it makes the ice with.

Do you see any problem using the ice this way, or should I just wait the few hours for it to cool?

I kind of like cooling the wort externally. When the boil is done, I put my whole boil pot - four gallons, stainless - into my kitchen sink, which will have about six inches of ice water (I just empyt out what my ice maker gives me). This cools down the wort nicely but nothing actually comes into contact with the wort itself. When I brew during cooler months, I just put my water outside to chill and skip the wort chilling.

For many years I have been brewing 1.5 gals and place 4 - 1 gal jugs of PUR filtered tap water into the freezer 4-5 hours prior to brewing.

I have never had a problem with my final (topped off 5.25-5.5 gal) brew temp being in the high 60's to mid 70's.

I place 1 gal of (freezer) water into the (plastic) primary and place a nylon net over the top of it (held in place with clip-on clothes pins) to catch the hops then sparge the hops with the remaining water.

Plus the water has not been boiled so it has plenty of oxygen in it to aerate the wort. I just stir it in for a few minutes prior to getting my temp and gravity readings.

I've used ice made from straight tap water without trouble, but it wasn't from an ice making machine. The machines tend to get infected over the years.

The last brew I made, I filtered 1.25 gallons of water into a sanitized ice cream bucket, snapped the lid on and froze it solid the day before I brewed. When I was done with 3 gallon boil, I added the huge ice cylinder to the wort and it cooled it so much that the block never really melted all the way. It got down to pitching temp in about 10 minutes.

i've used ice everytime i've brewed- i ususally try to freeze my own sterilized/filtered water, but have often cheated with store-bought bulk ice and haven't had any problems.
For the quickest cooling put the ice directly into the fermenter and siphon the wort onto it (once it cools to at least 140F). If you wrap the siphon tube in a wet cloth it cools even faster.

As usual, five brewers, five different methods, all of which seem to work!