Please judge my tank maintenance.

[kandaila]

I have two male bettas in a divided 2.5 gallon tank with a clip on led light and a heater, no filter. I've been doing 50% water changes every other day and 100% every week. I've been noticing a thin film on the top of the water it almost looks like a type of oil. I've been adding prime when I get water out of faucet and one capful of betta basics as a conditioner when I change water. The film is still there even a few hours after a water change. I'm taking the water to be tested this afternoon, but any clues as to what this oil film may be?
I also have a couple questions about the water changes. When you do 50% do you vacuum the gravel or change water only? And with a 100% I've been removing all decorations and rinsing them and gravel. Is that good or too much?
I know bettas like a floating plant. Could I add duckweed or is my light not strong enough? Thanks

[LittleBettaFish]

Sounds like a protein film. It's harmless and happens when there is no surface agitation.

Duckweed does best with a decent lighting and nutrients in the water column (why it thrives in soil based set-ups). I have never had much luck with growing it in a tank that didn't have either of those elements. LED lighting is generally pretty weak, and may not even be the right colour spectrum for plants anyway.

Not to sure on the gravel front. I'll leave that for someone else to answer.

[waterdog]

First thing you need to do is get a bigger tank! A 2.5 is bare minimum for 1 betta, splitting it for 2 is just asking for trouble.

[LittleBettaFish]

No different from the other members here keeping their bettas in 1 gallon aquariums. As long as the OP keeps up with water changes and the bettas aren't getting stressed out by each other, I don't see too much of an issue with it.

At least it is heated and the water changed regularly.

[Oldfishlady]

Lots of different ways to successfully keep this species.
IMO/E-the 2.5gal divided-without a filter or live plants-with 2 adult Bettas-Water changes of twice weekly should maintain water quality provided that you don't overfeed, remove uneaten food within a reasonable time and feed quality foods.

What I would recommend-Twice weekly-1-50% water only and 1-90-100% with vacuum in all places you can reach without moving anything or if you don't have a vacuum the stir and dip method.
Leaving them in the tank for water changes to limit stress. You might need to do a full tear down every month and if you do-be sure and properly acclimate back to the tank- Or if you do cup weekly for a full tear down.

IMO/E-Keeping a Long fin male in a 1gal unfiltered long term is fine-provided that you maintain water quality. With some of the mature Long fin males-too large of space and/or water movement can be stressful and/or be the cause of fin damage. Not all Long fin male have problems with space and/or water movement either. IMO/E a lot has to do with genetics, nutrition and overall health.

The oily surface is most likely organic and generally not harmful-unless it impeded on gas exchange. It is usually caused by either-fish food, organics in the tank, things in the air on your hands...etc....Sometimes you can lay a paper towel over it and remove. By adding some water movement can help to keep it broke up so it isn't as noticeable.

Duckweed, may or may not do well, as LBF posted, the LED light might be an issue, however, if the tank get some natural indirect sunlight-it might do okay.

[kandaila]

I bought the tank before I started reading anything on here. If I did it again I would split a 5.5 gal. I like the way the divided tanks look and the boys get pretty board with each other quickly. They spent their first day flaring and now mostly just ignore each other. Do they make a super quiet filter that I could add? Or would I be able to plug it into the timer that runs the light? The tank sits directly next to my bed about 2 feet from my head and running water/buzzing air pump would drive me nuts all night. (Eventually it will be moved to a seperate room once we move out of out apartment.))

[LittleBettaFish]

I have a sponge filter in the tank that is directly beside my bed. The air pump is actually located a couple of metres away under my chest of drawers and is pretty quiet. I just ran a longer length of airline tubing up into the tank.

I have the sponge filter on very low as all it is there for is to provide some surface agitation. I can't really hear it all that much.

I find sometimes internal filters or HOB filters are actually fairly loud, especially at night when there is no other sound. Plus in a tank that size an internal filter might take up too much room or provide too strong of a current.

[kandaila]

Thanks OFL. I think I might try the duckweed. I do get some natural light and the fish store near me has tons its almost just a nuisance so its super cheap. . I do notice that Nightshade (the larger one) is pretty lazy. He spends most of his.time chilling on his plants. Star is more active but he is younger too.