Substrate

[Brendan42]

I live in Seattle and don't have access to SD sand. What would be a good alternative?

 

[davelin315]

The consensus seems to be aragonite sand/oolitic sand (whatever that is). Depends on what you want to do with your tank, though. If you're using a DSB, then you want to go with the suggested mix (I have no experience with a DSB, so I couldn't tell you what it is, just that I'm starting to experiment with one). Otherwise, choose what you like. In my reef, I have a mix of large crushed shells, crushed coral, aragonite, and a tiny bit of sand. I like how it looks, it doesn't get compacted, and it provides a pretty stable base for building and stacking rocks. It's only about 1 1/2-2" at deepest, and down to about 1/2" in some places. To each his own, but there's a lot of experience on this bb, so ask about a specific type of substrate, and you'll probably get more responses.

 

[Carpentersreef]

At the risk of being laughed and pointed at...

I would look at Ecosystems Miraclemud. Seeing how you are a student though, it may not be an option. (expensive)
I've seen opinions that it is no more than backyard dirt, but I have no confidence that typical dirt would not have a lot of harmful chemicals in it. I thought of sterilized potting soil, but if it contains a lot of peat moss, it will only float to the top of your aquarium and cause further problems.
I bought 40 lbs of ecosystems mud today (yah everybody, never mind how much it cost

) and put smaller and larger sand on top of it. The playsand that HD carries up here is large brown stuff, not useable in a reef for my liking.
Just like Davelin, I am just starting to experiment with DSB.
Size DOES matter in a DSB. Do searches on this BB and check out anything Dr. Ron Shimek has written lately on the subject.
Also check Reef Central BB.

Read,
Read,
Read.

Mitch

 

[2poor2reef]

I use oolitic aragonite, mixed with some live sand. It works very well for me.