The best "decorations" in saltwater are living things! Coralline algae inevitably grows over anything fake, so you can't really use the same decorations as freshwater. Corals and anemones are going to look much better than plastic anyways. They will need the tank to be build around them, so there is that. Saltwater is harder than freshwater, but it's still doable for almost everybody.
The first step to starting out in saltwater is research. The second step is more research. Next, comes more researching. It's best to start out with all of the knowledge you'll need. I did about 8 months of research before I started, and I wish I'd done more. You don't need to take that long, but you definitely should know what you're doing before you start. There are lots of great resources out there. I'll link a few here, as well as a good video explaining the basics of saltwater.
A few suggestions that I'd like to make based off of my personal experience:
1. Start your tank with live rock from the ocean. You'll see lots of people talking about how dry rock is the future, but they're usually trying to sell it to you. You won't regret going live.
2. Either learn to quarantine fish, or find a good source for fish that have already been treated. You might be fine going without quarantine, but you're also probably going to be fine driving without a speed belt.
3. Don't bother with SPS corals as a beginner. They're pretty, yes, but they aren't worth the headache and constant vigilance with parameters they require. I'm only doing soft corals and anemones in my tank, and it's much more fun.
4. Don't trust anything which claims to be able to solve all your problems. It's probably snake oil at best, and can sometimes be harmful. There was a whole fiasco a while ago with a product that claimed to kill algae. It did, but it also killed corals, and contained algaecides banned in the EU. Better safe than sorry.
5. Find things with manual controllers. Apps give me a headache, and they can be difficult to figure out.
6. Plan every change you make and everything you add weeks in advance. It'll prevent nasty surprises.
7. Don't panic over algae. Most kinds go away by themselves in a while, and those that don't can be treated.
8. Take your time. Nothing good happens quickly in this hobby, and you'll get the best results by going slowly. I didn't add corals until my tank was 4 months old (and 3 months for fish), and I haven't lost a single one yet.
And most importantly...
9. Enjoy your tank! It's meant to be fun, so don't try to micromanage or make it unnecessarily difficult.
Welcome to the hobby!
The first step to starting out in saltwater is research. The second step is more research. Next, comes more researching. It's best to start out with all of the knowledge you'll need. I did about 8 months of research before I started, and I wish I'd done more. You don't need to take that long, but you definitely should know what you're doing before you start. There are lots of great resources out there. I'll link a few here, as well as a good video explaining the basics of saltwater.
The Supreme Guide To Setting Up A Saltwater Reef Aquarium
The Supreme Guide To Setting Up A Saltwater Reef Aquarium This article was sponsored by @MarineDepot at www.marinedepot.com. Introduction The marine environment is one of the most complex systems on the planet. The aquarium you are about to set up is only a tiny sliver of the vast ocean...
www.reef2reef.com
The Best Guide for Starting a Reef Tank | Reef Builders | The Reef and Saltwater Aquarium Blog
Setting Up Your First Aquarium If you want to start your very own reef tank, you’ve come to the right spot. Reef Builders will take you step by step on how to setup a reef tank from scratch. And…
reefbuilders.com
Set Up a Saltwater Aquarium
So you want to setup your first Saltwater Reef Aquarium? Congratulations on taking your first step into the wonderful world of reef aquatics.
reefs.com
A few suggestions that I'd like to make based off of my personal experience:
1. Start your tank with live rock from the ocean. You'll see lots of people talking about how dry rock is the future, but they're usually trying to sell it to you. You won't regret going live.
2. Either learn to quarantine fish, or find a good source for fish that have already been treated. You might be fine going without quarantine, but you're also probably going to be fine driving without a speed belt.
3. Don't bother with SPS corals as a beginner. They're pretty, yes, but they aren't worth the headache and constant vigilance with parameters they require. I'm only doing soft corals and anemones in my tank, and it's much more fun.
4. Don't trust anything which claims to be able to solve all your problems. It's probably snake oil at best, and can sometimes be harmful. There was a whole fiasco a while ago with a product that claimed to kill algae. It did, but it also killed corals, and contained algaecides banned in the EU. Better safe than sorry.
5. Find things with manual controllers. Apps give me a headache, and they can be difficult to figure out.
6. Plan every change you make and everything you add weeks in advance. It'll prevent nasty surprises.
7. Don't panic over algae. Most kinds go away by themselves in a while, and those that don't can be treated.
8. Take your time. Nothing good happens quickly in this hobby, and you'll get the best results by going slowly. I didn't add corals until my tank was 4 months old (and 3 months for fish), and I haven't lost a single one yet.
And most importantly...
9. Enjoy your tank! It's meant to be fun, so don't try to micromanage or make it unnecessarily difficult.
Welcome to the hobby!