Hi all,
I've had bettas for about 6 years now. I recently upgraded to a 20 gallon tank with two tank dividers to house three male bettas. Until recently I had all three male bettas in a similar setup but in a 15 gallon tank.
I also purchased a whisper internal filter for 10-30 gallon tanks. My one betta who was in the section with the filter didn't seem to like the current much so I bought one of those ceramic hollow log/coral things that I could put with it's end up to block the out flow of the filter.
This seems to work well as my betta is swimming all around the tank now, and even loves to swim inside of the cramic coral thing.

The middle section has a heater designed for 20 gallon tanks.

The third section houses a pump attached to an air stone.

1. Is this an okay setup for my bettas? I use plastic plants (flourescent colored) and some are kind of sharp, but I never see my bettas have any problems with them.

2. I could have sworn I read somewhere (maybe www.bettatalk.com) that bettas normally do breathe from the air when they are in small shallow areas, but given a large enough area, they will actually use their gills (if there's enough oxygen in the water). I'm really beginning to think that this is true as I never see my bettas go go the top of the water anymore (they used to when I had them in smaller tanks say half a gallon each).

I also add aquarium salt to help keep them healthy.

That sounds like a great set up, you should post a pic or two

As for the plastic plants, some members have had problems with them. I once had a goldfish lose an eye to one. But if you feel your bettas are ok with them, that's ok. You could always switch to silk or real plants someday.

And yes, you're right that bettas will breath through their gills when there's enough oxygen in the water, which your tank likely has. Their ability to breath through their mouths is what makes people keep the poor things in cups and vases
They won't run out of air like other fish will...but they will be poisioned by their own waste.

I used to have my bettas in 3 small tanks (half a gallon to a gallon each). I've had fantastic luck with my bettas living anywhere from a year to two and a half years or more.

I used to keep a goldfish in the 15 gallon tank, but had trouble keeping them alive for some reason.

But the bettas have done great, they've never gotten sick and they've been together in the same tank almost two years now.

The salt really seems to help keep them healthy, plus I change out some water every two weeks.

I used to have a Lees Economy Corner filter, but it cracked and i replaced it with the airstone.

Is changing the water every two weeks ok? How much should I change?

I only feed my bettas once a day and one day a week i skip feeding to give them a rest.

When changing water I put cold water in a bucket and let it age for a day or two, then add a little bit of water conditioner and stir it in.

I've always had the water at room temperature. I know you're supposed to have the clean water the same temperature as the tank but how do you do this? I've read that using warm water for fish isn't good because the heat from a water heater does something to the heated water (hot water from the tap i'm talking about here).

I've also been thinking. Should I get a new corner filter? Or is the whisper internal filter enough (it says it's for 10-30 gallon tanks but I don't see a gph on it anywhere). I used to have the corner filter in there for the farthest corner away from the filter because i was afraid the water wasn't being filtered properly because of the dividers.

I do love the internal filter though, no intakes to worry about, no impellers and they're quieter. Once I solved the problem of the out take being too strong by leaning the creamic oral against the filter, it seemed to work out great.

You obviously care a lot about your fish

I think the filtration you have is good, bettas don't produce as much waste as goldfish.
If I were you I'd change the water a little more frequently, I generally do my tropical tank every week, and I change 1--20% of the water. I use tap water and match it to the tank temp (I have an aquatic thermometer) then I add water conditioner to remove cholorine. I've also used your method of leaving water out for a few days, you can keep doing that if you like.

Thanks for all the great help!

I used to use hot water mixed with cold to get the right temperature to match my tank, but then I've read that something in the process of heating up the water is not good to add in a fish tank? Something like it becomes calcified or something?

yeah I do love my little guys. I try to provide a good home for them and take care of them (just bought more aquarium salt today actually to add in the water when i do water changes..it seems to help keep them healthy).

I'll try to do the water changes once a week.

Hi Kevin! Sounds like you are doing a good job of caring for your little guys. As for the heated tap water, it is fine. I do not let my water age, but temp match it straight out of the tap and treat it with Prime, then in the tank it goes. No worries!

Chrissy is right, weekly water changes are important. Even though bettas don't create as much visible waste, they still foul up the water via ammonia and such. It is a good idea to aim for 25% water changes weekly. JMO!

Thanks for all of the suggestions. I've been changing the water every week now. It's probably good that I do it anyway since I have to refill the water that is lost due to evaporation.

I must say I love the internal filter much better than the hang on the back filters. It doesn't have an impeller, so when I clean it I just take it out, rinse it off, put the media back in and presto. And if the motor becomes loud you just open the cover and rinse it in cold water. So much easier to maintain.

I'll use the hot water. Thanks for all the help!