Betta Care: Let's talk decor

Decor is all the stuff in your tank that's not water or your fish.

You have decor for two reasons: 1) To make the tank pretty and something you like having in your house, 2) To replicate the natural environment of your fish.

This means you have three things to keep in mind when you're decorating (aquascaping) your tank: 1) Will it make my betta feel safe, 2) Do I like how it looks, and 3) Will it hurt my fish?

Pshaw, Polly, I'm not just sticking random shit in my tank. I got it from the pet store! I don't need to worry about if it'll hurt my fish. 

Bad news, Italicized Strawman.  A lot of decor you can get at the pet store will hurt your fish. Some stores sell cheap (or overpriced) decor that has paint that'll flake off into the water. Also, betta fish have very delicate fins. Sharp or rough decor can rip right through them.

This is just the stuff that's not currently being used

Luckily, I have a lot of decor hanging around, so I can talk about the good and the bad.

The sand, gravel, or stones you put on the bottom of your tank is called substrate. There's several different kinds, all with good and bad sides.

I like gravel. It comes in a lot of colors, it's cheap, I find it easy to clean, and it's reusable. It's the only substrate you can use with an undergravel filter. I suggest getting about 1 pound a gallon for your tank (though this depends on the shape of the tank).
Some people don't like gravel because it requires a more thorough vacuuming than sand does. You can't grow live plants in gravel, and it's dangerous for bottom feeders like catfish to be on. (side note, don't put gravel in your goldfish tank. They try to eat it and frequently choke).

The cup on the right in the above picture has glass stones. Large acrylic or glass stones are great for unfiltered tanks. They're easy to dump out, rinse off, and put back in the bowl. You don't need to worry about them going down your sink like you have to worry about gravel.

Some people use very large stones, 3"+, in their aquariums. This works really well for goldfish, but betta will try to swim through any little hole, and can get caught. If you use large stones, make sure they are smooth and that there are no spaces a fish could get stuck.

2.5gal tank with sand

Sand is another popular substrate. You can buy a bag of play sand at the hardware store for $4 for 20 pounds, which will be enough for most tanks.
When you're buying sand, make sure you're not getting marine sand. Marine sand has salt in it and isn't good for betta tanks. Play sand and pool filter sand both work for fish.
Sand is difficult to remove, and if you frequently rescape your tanks it is also very difficult to clean up and move. It's easier to bury plants in. You can't use it with a buried heater and you can't use it with an undergravel filter. It doesn't come in any fun colors.
Some people have an easier time cleaning sand than gravel, or feel they do a more thorough job cleaning it. A lot of people like that it's more natural looking. People who have tanks with live plants like sand for planting in it.

You can also choose to have no substrate and just have a bare tank floor. I like this because it makes it easy to tell if the tank is clean and very easy to vacuum, but it's harder to add more water without the decor sliding around.

It's also important to remember that if you're going to divide a tank, you need at least an inch of substrate to bury the bottom of the divider.

Now, other stuff!

I suggest that every betta enclosure has some kind of cave. A cave is anything a fish can swim into and hide. You can buy cool ones that look like pirate ships or skulls, or you can use a mug or teacup or terra cotta flowerpot turned on its side (no metallic decorations, though, as those can be toxic).

I call these guys ornaments. They're hard decor that isn't meant to look like plants. When Twister had the triangular arch in his tank, he liked swimming through it. It's possible to put an airstone under the lighthouse and have bubbles come out the window, which is pretty cool looking.

DON'T TOUCH MY LEEF!!!!!

Here's some betta-specific decor. The left is a betta log, and the right are betta leaf hammocks. If you have an older fish or a fish you've noticed sleeping on other things in the tank, it can be nice to give them a leaf that's meant specifically for sleeping on, or a log for sleeping in. Currently, none of my tanks have betta leafs or betta logs.

Before we go on, there's two types of bases for plant decoration. Bottom left is my favorite, the weighted base. You can bury the end in gravel or sand, or have it just sit on the floor of the tank. I like these because if I accidentally unbury one, it doesn't float to the roof of the tank.
The top and bottom right ones have cups in the bottom that you have to bury to make it stay down. If you have sand, these stay better than if you have gravel. They do not work at all for bare tanks.

Now, on to plants:

Silk plants (which are made from fabric, but not necessarily silk) are my favorite for betta fish. They are soft and don't scratch delicate fins, and a lot of them have big leaves to sleep on.

Here's some soft plastic plants. They don't have sharp edges. Even though some of them are made of hard plastic, they don't have bits that are easy to catch a fin on.
If you want to test if a plant is good for your betta tank, put on some tights and rub the plant on your thigh (or pretend you did). If it snags your pantyhose, it's too sharp.

And here's the sharp plants that I suggest you avoid. If you grab one of these in your hand and squeeze, you can feel it digging into your hand.

When you're actually scapeing your tank, put short plants at the front and tall plants at the back. Petsmart sells these filler carpets that are great for cutting up and adding little decorations. That's what that front piece is. Here Casper's got a clay pot for a cave.

Mr Tipsy's cave is wider than his apartment, and has to be at an angle. Again, note the tall plants in the back and short in the front. This isn't for any health reason, it's just nicer looking in general.

Bo's got a lovely piece of driftwood that I made sure was smooth before I put it in the tank. For the first few months, the driftwood turned the water brown and I had to use carbon in my filter to keep the color away. Now, however, it's done leaching tannin and just looks pretty. Driftwood can help lower your PH, and the tannins they stain the water with don't hurt your fish.

And here's Twister's dragon. The dragon has an airstone in it to let it breathe bubbles, but I disabled it because Twister already had the UGF lift tube putting bubbles into his tank. Twister doesn't have a cave, and instead has a very dense group of tall and short plants in the back of his space. This is because when he had a cave, he'd still hide in the plants if he was scared, so it seemed better to replace the cave with more plants.

Well, that's more than anyone ever needed to know about fish tank decorations. Have fun, folks.