Starting a salt water aquarium???

Saltwater tanks are INCREDIBLY hard to take care of. I had freshwater for a long time, I thought I knew how to take care of an aquarium, what could be such a big difference. Man was I wrong! Just cycling the tank is an ordeal. All that stuff you read about cycling a tank in freshwater that you ignored? Well, in saltwater it is incredibly more difficult. Its also expensive. On the other hand, its 5 gallons (an impossibly small amount for just about anyone with fish) and you want to try, so you might as well try anyway! Its not going to cause the end of the world or something. something that no one told me is that you cannot just mix the water and put it in the aquarium, and expect things to be okay. You have to mix it and then have it sit a day or two with a pump or airstone or something moving it around so all the chemicals mix and react with each other and precipitate and everything. You cannot use tapwater to mix with the salt, it has to be distilled or reverse osmosis or the water will kill everything. You have to wait for the water to cycle before you add fish, and that takes about six weeks. I know you aren't keeping fish. Anyway, you should keep mixed saltwater around in a big container somewhere so you can change the water a lot. You can't use fresh saltwater to change the water. *sigh* Anyway, I think you should try it! Just be very careful. I would actually prefer a saltwater tank without fish in it, saltwater fish die very easily. If your pump goes off for a couple hours, maybe an hour, all the fish will be dead. Dead. All the fish. Dead. That doesn't happen in freshwater. Anyway, try it! It could be very fun.

Don't bother.

Salt water is crazy hard to maintain, and the smaller they are, the harder it is. Even experts have difficulty with big tanks, and they will tell you not to attempt anything smaller than 50 gallons.

The issues:

Small tanks have problems holding heat.

Small tanks have problems maintaining proper salt levels.

It's difficult to maintain the light levels needed for small tanks.

Fresh water tanks are very forgiving, and the animals living in them aren't as fragile. Salt water tanks need almost constant monitoring. They are very high maintenance, and even if you do everything right, you can have a mass die off for no apparent reason.

This is an "all or nothing" thing. If you aren't willing to pop for a 50 gallon (or larger) tank - don't bother with salt water at all. Get yourself another betta, or just make that tank into a terrarium. Get some Venus Fly Traps. They'd love living in there.

Don't do it

You need to go bigger around 55 gallons is Ideal and they are hard work .You need to do a lot of research and get it wrong its an expensive mistake .