Really depends on what kind of fish you want. I have a betta-only sorority in a 10 gal and I went with a little filter that you put inside the tank. It's rated for 6 gallons so the flow is slower than a lot of the bigger filters. It's working pretty well.
If I were to do over, I think I would get a slightly bigger HOB and put a water bottle baffle on it to diffuse the flow. I think the little filter has a hard time keeping up since there's not enough media in there for bacteria to grow on. I've had to add media/sponge myself and that has helped a little.
Hi Granny, welcome to the world of bettas. There are many different options for filters but for bettas you want one with a low current. You can do this by buying a filter with an adjustable outflow, such as the Aquaclear 20. Or you could put a baffle on whatever hang on back (HOB) filter you buy, as RobertTheFish said. If the current it too strong you can tie a aquarium sponge to the outflow of the filter.
I really recommend the Aquaclear 20 as it ensures that all of your beneficial bacteria (the bacteria that keep the tank healthy and break down your betta's waste) stays alive and well in the filter. It comes with 3 different medias-- aquarium foam that takes the physical particles out of the water, carbon which takes the chemicals and odor out of the water, and lastly a media that allows for the good bacteria to flourish on it. Since you change these out at different times, you will always have the beneficial bacteria in your tank. Just my recommendation though. :) Good luck.
Hi Granny, Welcome to the forum and the wonderful world of bettas! I have two 10 gal tanks and one has an Aquaclear filter and the other has an Aqueon filter. The Aquaclear has a flow regulator, which means you can adjust it slightly for slower or faster water flow. I'm not sure if it's just my filter, but the slow flow isn't very slow at all. So I have baffled both of my filters. Baffling simply means that you alter the flow of the water as it comes out of the filter and back into the tank. There is a "sticky" on this forum that will show you two different ways to baffle your filter. Go to "Betta Fish Bowls, Habitats & Accessories" and click on "Step by Step Filter Baffle". You'll see two options: the water bottle method and the sponge method. I've tried them both and both options work great for me. Personally I like the sponge better. In regards to your 10 gallon tank, please be aware that you'll need to "cycle" it. This process takes anywhere from 4 to 6 weeks and it's a very important process! The life of your fish depends on it! There is another "sticky" on this forum that will teach you all the basics of cycling your new aquarium. Again, go to "Betta Fish Bowls, Habitats & Accessories" and click on "Beginners Guide to the Freshwater Aquarium Cycle". It's packed with all the information you'll need. I believe that sticky also talks about Freshwater Water Conditioners. Please be aware that you will also need to treat any and all tap water that you add to your tank. The chemicals in tap water will kill your fish. Again, I'm sure it's in the sticky. There is also an important step to acclimate your new fish to your tanks water temperature before adding them. This information is listed under "Betta Fish Care". You'll want to click on "Your New Betta, Day One!" So there is lots of new fun stuff to learn!! This forum is awesome and you'll find all the information you need to set up a new home and acclimate your new friend. So enjoy the process. There's a lot to do and learn but it's worth it. Bettas are awesome fish and I'm always creating new ways (and tanks) to buy more! Good luck and again, Welcome!
Oh,how wondeful everyone here is so kind and informative(yes I am a grandma)
I am trying to find out everything I can,to take good care of my Betta.
I was at the aqaurium place yesterday and the owner,said I could buy a Betta and use Zephyhills Spring Water to change my bowl until I get my tank cycled(though he said it wasn't necessary and I could keep my Betta in a tiny bowl/how frustrating that was,to know he was probably telling others that/poor Bettas)
I am reading all I can here and am going to get some books from the Library on Mon as well.
You do not nor should you use spring, bottled our distilled water unless there is something wrong with your tap water.
It lacks minerals and such that the fish need to stay strong. Its also way way more expensive.
Instead, buy water conditioner from the store. Out removes harmful things like chlorine from tap water. After it is used, its safe!