Betta fish floating still, not reactive much

Tank
What is the water volume of the tank? 29 gallons
How long has the tank been running? Since November 2025
Does it have a filter? Seachem tidal 55
Does it have a heater? Yes
What is the water temperature? 79.1 currently, usually around 78.5
What is the entire stocking of this tank? (Please list all fish and inverts.) 1 betta, 6 kuhli loaches, 1 mystery snail

Maintenance
How often do you change the water? Once a week
How much of the water do you change? 30-40 %
What do you use to treat your water? Seachem prime
Do you vacuum the substrate or just the water? Both

*Parameters - Very Important
Did you cycle your tank before adding fish? Yes
What do you use to test the water? API test kit
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.
Ammonia: 0
Nitrite: 0
Nitrate: 5-10 ppm
pH: 8
GH: I can’t tell. I’m using the api gh and kh test kit and it says gh test is over when it turns from orange to green but it was green tinted from the first drop
KH: took 15 drops to get yellow from blue so at least 214.8 ppm though definitely more, the conversion chart only goes up to 12 drops

Feeding
How often do you feed your fish? 6 days a week with one fasting day
How much do you feed your fish? 4-6 pellets once a day
What brand of food do you feed your fish? Fluval bug bites and ultra fresh shrimp patties
Do you feed frozen? No
Do you feed freeze-dried foods? No

Illness & Symptoms
How long have you had this fish? Since may 2026
QT Used….Yes/No, ……if Yes, how long? No
How long ago did you first notice these symptoms? 1 week ago but it’s more noticeable past two days
In a few words, can you explain the symptoms? Floating aimlessly, not reactive, not eating because he’s not reactive, possible fungus growth on gills/head
Have you started any treatment for the illness? No
Was your fish physically ill or injured upon purchase? No
How has its behavior and appearance changed, if at all? Head looks like it has white film, looks sickly, and he’s not active at all, mostly just floats still


Explain your emergency situation in detail.
I’ve noticed my betta fish being less active and standing still a lot over the past week, I thought he was just bored but for the past two days it’s a lot worse. He is mostly floating at the surface or at the bottom now with his head up or his head down completely still. He doesn’t really react to movement in the water unless it’s really close to him. He doesn’t eat because he doesn’t react to the pellets, it’s like he’s blind but he’s not blind, his eyes look alright and I see him moving them around occasionally. And now It looks like he has like a white film on his head and his gills, like a fungal infection, but It’s really hard to tell. His fins look good and none of my other fish are acting strangely at all. I included pictures but my phone isn’t the best so I couldn’t get very high definition shots sorry

Hi, sorry to hear that — this does sound concerning; I'd treat it as urgent. A few thoughts:
Most likely cause:

• Combo of lethargy + white film on head/gills + not eating points toward columnaris (bacterial, not fungal — often mistaken for fungus because it looks cottony/filmy)
• True fungus usually shows as distinct cottony tufts on existing wounds, not a general film — so bacterial seems more likely here

Before treating anything, rule out water quality first:

• Test ammonia, nitrite, nitrate, pH
• A sudden ammonia/nitrite spike alone can cause this exact lethargy + "not responding normally" behavior

Quick info that'll help others diagnose:

1. Is he alone or with tankmates?
2. Current water temp?
3. Any recent changes — new fish, filter clean, substrate disturbed, temp swing?
4. Can you get one clearer close-up of the white area? (Cottony vs. flat/slimy changes the likely diagnosis)

If it turns out to be columnaris (bacterial):

• Common treatment combo: aquarium salt + lower temp slightly + antibacterial med (API Furan-2 or Maracyn)
• I'd wait for photo confirmation from a couple more experienced folks before starting meds, since bacterial vs fungal treatments differ

Hope for best...

Hi, sorry to hear that — this does sound concerning; I'd treat it as urgent. A few thoughts:

Click to expand...

I’ve been battling a detritus problem so I’ve been vacumming the substrate more but I only do a water change once a week so not sure if that was the problem. Also none of my other fish have the same symptoms, and since columnaris is really contagious, would that rule it out? Here’s some more pictures, sorry that the glass is so dirty. The last pictures, you can see some sort of white growth on this chin? I’m really worried if this is columnaris my parents will not let me get another tank to quarantine him away from my loaches

No, it does not rule it out. Columnaris is already present in most tanks and it takes the fish that is run down first, so tankmates staying clean is normal rather than reassuring.

The order bothers me more than the tankmates. He was unresponsive for a week before the white showed up, and columnaris usually moves faster than that, especially at pH 8 and 79.

You do not need a second tank to isolate him. A bucket with a heater and an airstone is a quarantine.