Hi and Thanks!

[Canadian Man]

WELCOME TO CANREEF!

1. I use a little silicone on the oring as well. Just make sure you put the oring/flange on the inside of the tank where the water will be contacting it.

2. Weather you need fans or not can depend alot on your hood design.
If you are just planning on running the pc's then I would not bother with the fan's.

3. There is allot to tell you about a basement sump. You should probably make the trip here some time and see it in person rather than me explaining it all but I know you will learn alot if you see it. I cut the holes in the wall not the floor and I made my hole on the return air feed of my house so when I need to patch it back up sometime I can just put a grate on the wall and I'm done . Basement sump Is great!!! I have no worries about space!

4. buy a salinity mesurer of some sort and Tony is correct. I use a little less than 1 cup per 2 gallons.... When I make a 25g water change It's about 11 or 12 cups or so.