Sand or Gravel?

Hi!

So I am starting my first tank from what I believe used to be a FW tank. Currently I have 50 lbs of river gravel/rocks in it and was wondering if this was okay for SW (as opposed to sand).

I like the idea of having a really thick substrate, so is it okay to mix sand and gravel? Could I pour another 50 lb of sand on top of the gravel? I thought it might look neat to have a "river" of sand going through the gravel.

Also, I wasn't very sure about diseases and algae from the gravel's previous use, so I boiled every single pebble before setting it up. For future reference, was this necessary?

Thanks for the tips!

 

the good thing about sand is that if you use the correct kind, you get great buffering ability and your ph and alk will stay stable. you wont get that with the rock, but you could mix them if you want. just keep in mind that the bigger pieces of rock will always end up on the top of the sand, even if you bury it. i like the look of clean white sand, so i would go that route, but to each his own.

 

I would deff go with sand....I thought crushed coral looked sweet when i started but 1 year later i hate it and i cant wait to transfer my tank (in 2 weeks when i get my stand and canopy done) to have a nice white sand bottom it looks so nice and cleann

 

my first marine tank set up was from FW to salt, and i used the gravel from my FW setup to take the cheap way out, it looked crap and i changed it about 3 months in what a nightmare.
this is a decision u want to make before u stock your tank, ive never seen a marine tank that looked good with out sand

 

ok the river of sand through the rock would never be possible do to current in the water. the sand would shift and scatter. also as mentioned above sand creates a biodiversity of algae and other things required to have a marine tank. you could use the rock but you would need a really good filtration system with bioballs or biochem stars to make up for the lack of biodiverse organisms. another way to do this is to use an in sump refugium or have a compartment in the sump with live rock and a very deep live sand or miracle mud bed. on my 20 gal. i have arag alive substrate and live rock. but for extra diversity because i cant afford the extra live rock i use biochem stars in my hang on back filter. www.doctorsfosterandsmith.com is a good online source for good reliable filtration and other acsessories.