John,
I've been using Instant Ocean with good results. By the way, it doesn't seem to dissolve well/quickly either. I did use a box of Oceanic Natural Sea Salt mix, and it dissolves very quickly. The mix is extremely fine and was easy to use. I've heard mixed reviews on the quality of the product though.
I upgraded from a 55 to a 125 just over two months ago. The process actually went pretty smoothly. For what it's worth, here's how I approached it:
- Set up the 125 tank and stand - leveled everything and got it placed just how I wanted it. (I actually had to move the 55 to do this because it was set up where the new tank was going).
- Put all livestock and rock in 5-gallon buckets with powerheads (probably not necessary, but made me feel better).
- Placed new substrate in the 125-gallon - used about 5 cups of my old substrate on top of new stuff to seed it. I had several anoxic areas in my old sandbed and didn't want to transfer too much of it over.
- Drained as much of the water from the 55 as I could (probably around 85-90%) and added it to the 125. Then I filled it about 75% with new saltwater.
- Added the live rock and corals - I didn't acclimate them, but they didn't seem to mind. Probably would have been a good idea tho! I even have a bubbletip anemone that was attached to a huge piece of rock - had no choice but to put him right in. No problems!
The move from 55 to 125 took a total of about 3 hours - not enough time to really stress any of the livestock. I also made sure to adjust the thermostat to 77 degrees so the temps stayed stable in the buckets.
I have been monitoring the water parameters every week since the move and have not had any "bounce back" in ammonia or nitrites. I didn't add any new livestock for a month after the move.
Good luck with your move!
David