Let's talk bubble nests just out of curiosity. While I was cycling my tanks they live in now they was living in heated non-filtered kritter keepers. Now they live in a 10/5 gallon tanks with sponge filters. They used to make bubble nests every water change in their kritter keepers. It never failed change the water next day a new bubble nest would be present. Now they haven't made a bubble nest in 3 weeks being in their main tanks. I know for a fact my blue Betta is healthier in the more stable cycled tank as he used to have chronic fin melting/rot and tail biting issues that are now cleared up. My red Betta is just a happy go lucky guy and healthy as ever with his tank. I'm using a sponge filter on one of the tanks and a baffled internal filter that barely causes any current as Cosmo can actually hover right under the sponge that is creating the baffle with no difficulty. The water checks out fine as far as parameters, temp is 78-80*, and currents should be minimal. Any other reason a Betta wouldn't build a nest in a larger tank?
I have a fairly young cellophane male who wasn't interested in nest building until I started giving him Oldfishlady's oak-leaf tea a couple times a month with his water changes. Now he loves to construct....CJD
My Betta wasn't interested 2, 4 a while. I showed him a picture of a female Betta.
Taped it on tank. Stayed there 4 a whole night. Next Day, saw a bubble nest took away female, stopped. After a week, I found a bubble nest. He's making it bigger right now. And don't worry, Bettas don't always make bubble nests when they're happy. It's sometimes just instinct.
Last week I thought I saw a pinhole in my female's tail... Grabbed her out of her 5 gallon and floated her in "Killer,s" 10 gallon while I cleaned her tank. Killer- the cellophane I was talking about the nest building- was emphatic and she liked him ,I think. Let them see each other for three days like this... almost sent for "fry food" but his tank has a mixture of river pebbles and sand on floor so not ready to let them progress. Anyway what a nest he had and I liked the way he handled the whole episode so I intend to get them back really together soon. She built a nest too. Not great but not bad! And I was worried he was too small for her-- she's feisty and he's a little smaller than her... but I really think he'll be okay. No nest since I took her away- I,m going to make some tea and see if that induces him to make another nest. If I'm right in my thinking - he'll have a nest tomorrow morning when I get home from work.
Both my boys were building them in between their weekly 100% changes. Now they don't. Ludendorff used to have a habit of making them and tearing them down a day or two later (like he was giving an ultimatum to potential females lol )
They don't always build nests, you can tell if they're happy from other things too, like activity, willingness to explore, inquisitiveness, and flaring etc.
I've found very few bubbles nests since I started using bubble filters. In my case I know it is attributed to surface currents as I see the duckweed whirling around the tank quite often.
Another factor that affects bubble-nesting is air pressure. Most people don't think about it, tho. Storms are often preceded by low-pressure, and fish are very sensitive to these changes because low pressure means rain is coming. And rain means more water in their homes so they can expand their family without fear of overcrowding.
Nests are affected by air pressure (points to koimaiden), temperature, presence of other bettas, and general care.
I always have nests. I keep my bettas in immaculate water (changing 100% daily), with jars near other bettas, kept at no less than 82F, and fed high quality foods. Now with summer coming and some storms showing up I'm expecting even bigger nests.
Could be the current, even if there's only a tiny bit of it. Floating live/fake plants or IAL/oak leaves might keep the surface a little calmer and help them anchor a nest if they want to make one, too.
Could be since they have more room to explore now, they're distracted from building?