Betta - slowly declining health

  • #1
Hey everyone

I'm having some trouble with a betta that seems to have some sort of fin rot and has become lethargic. He's been getting by without any serious problems for about 10 months and throughout this time I've been making changes to make the water quality, lighting, and heating situation better. Lately though he's been staying at the bottom of his tank and his fins are deteriorating. He has stress lines most of the time which flare up even when I feed him.

Sorry this is such a long post. I'm pretty new to be asking in this much depth but I have a lot of information on the state of the tank setup which I think can help me narrow it down to one of a 2 things:

- possible mold in a pipe
- new heater is too powerful

I'm also a bit worried about some things that haven't changed much recently but might contribute:

- too much lighting
- poor vision adding to stress
- too much water flow
- age

My tank setup / parameters are:

3 bettas, age since bought: 1 year, 1 year, and 6 months
Name+type: Oscar: blue veiltail, Elmo: red crowntail, Snowflake: while double tail

3 tanks + sump (5+5+6+20 gal, total 36 gal). Pump in sump feeds tanks, overflow holes w/ tubing bring water back to sump.
2 out of 3 tanks are marineland hex 5's still using their pumps, filter pads, and biowheel
100W Eheim Jager heater + Fluval C3 with seachem purigen/matrix in sump
all water flow baffled by sponges and plants
2L coke bottle stuffed with filter floss between overflow tubing and sump
12 hours of light on a timer. lighting level has been lowered a lot recently

10 gal water change every 1-1.5 weeks (no top ups)
10 gal water aging tank with heater to avoid shock (ph of tap water rises from 7.8 to 8.2 after 24-48 hours)
1 to 1.5x recommended amount of prime for water conditioner

pH: 8.2
ammonia: 0
nitrite: 0
nitrate: usually undetectable, once read up to 5ppm
KH: 89.5 ppm
GH: 125.3 ppm
temperature: 80.6F to 81F


The system is fully cycled, though the 2 oldest fish had to endure the cycling process with daily water changes (These are my first fish. The first was bought for me before I knew anything about fish, I've smartened up by reading these forums since). They survived and seemed not to care, but there was some fin damage which in Oscar, the veiltail, completely recovered. Elmo, the crowntail, still has not fully regrown but he tends to be very active and responsive. He's OK at the moment.

Oscar, the fish having problems now, was the trigger for me switching from the bowl he came in to a 5gal tank. He started to be completely covered in a thin fluffy white film, even covering his eyes to the point where they couldn't be seen. He looked like he was going to die. After 1 week in the 5 gallon tank he seemed to fully recover but I suspect he has had vision problems ever since because he has trouble tracking his food and getting it in his mouth on the first try, though his appetite is normal. The other two fish are ravenously hungry and fast. This problem was 10 months ago at this point.

Here's a picture of Oscar's fins as they are today:


Here's a before and after of Snowflake in the same system, who has some black lines on his fins that I don't think are a problem since they have always been paper thin but have never rotted away at all. I'm curious if this could be a water problem but so far I've been thinking it's just an unrelated color change:


Anyways the main thing I'm worried about is the mold (or algae). I have some pictures of something I see growing in one of the overflow tubes that looks like either mold or some sort of black / dead algae. The water going down the tube doesn't necessarily touch every part of the tube so I think some moisture may have led to mold. There is some regular algae around the area so it may just be dead algae because I recently repositioned the tubes when I upgraded the sump from 10gal to 20gal.

Can anybody help me identify this?:


As for temperature, I've set up an arduino+sensors+database+webpage to monitor it. I used to have 3 25W Hydor Theos that were tough to get all calibrated the same. They couldn't really keep up with air temp changes. So when I switched from a 10gal sump to 20gal, I swapped them out for a 100W Eheim Jager. It can now keep the temperature within a much smaller band but I think may be heating up too quickly since Oscar's stress problems started when I did this switch, even though there is 10gal more water and it should be cleaner.

Two of the graphs on my webpage in particular are making me think it might be the problem. The daily temperature change has gone down but the hourly change has gone up. Where previously, the temperature would go up and down quite far in a day but do it slowly, the temperature now stays within 0.5-1.0 degrees F but it is always going down and then shooting back up, so the hourly change has gone up a lot. It takes longer to drop but the heater seems to heat it back up in a just a few minutes. I've read that they can only handle a change of 1F per hour but could it be a problem if it changes by say 0.3 multiple times per hour or heats up too quickly despite not changing a lot?

Looks like I hit the attachment limit so I'll put the temperature pics in another post.

If you have any ideas about what the problem with my betta could be, I would be very grateful!
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  • #2



  • #3
WOW! That is a lot of information haha. But good always good!

With your betta how old is he? Is there anything in his tank that he could possibly catch/tear himself on because this can lead to some pretty serious fin rot.
Have you considered maybe seperating him and treating him with a fungal medicine to clear the fin rot? Because sometimes when nothing else is working that is what's best. Melafix works really well for this. (Cleared my halfmoon banana right up)

I don't know about the mould I'm afraid, I do know that our tubes have a bacteria growing in them that is much like a fungus, but its just bacteria, however yours does look a bit like the mould that grows in a normal tank. It might not be anything to worry about, but maybe wait for other advice on that one.

If possible separate the little guy and dose him with a anti-fungal medicine! Good Luck
  • #4
I think you may be on the right track thinking it may be a temp problem. My son has his Betta in a 10 gallon on his dresser in his room, I have no heater in the tank,the little guy has been just fine for over a year and a half. It seems to me that if the problem started when you changed the heater it may be the cause.

The build-up in the tubing looks like algae the darker mould like stuff may be diatoms.

Hope your Betta get well.
  • Thread Starter
  • #5
Hey thanks for the reply

He's about a year old plus whatever age he was when he got to the store...

If it's a fungal problem would there always be some visual sign on the fish? Last time he had an outbreak he was completely covered. He looked like a little ball of white fluff. The tanks were separate at the time so the other fish wasn't affected. Still, somehow he was more active than he is now...

I just don't get why the other fish would be completely fine. They're all in the same system. Though when I say fine there's still the problem where my crowntail hasn't fully regrown his fins in over 6 months. They seem to have white tips that make it look like they're growing back but he's never made any real progress. With 36 gal cycled and crystal clear water I would have thought the water was fine except for the high pH (8.2) which I'm worried about messing with since I hear bettas can adjust to 8.2 and getting to a lower pH is stressful for the fish and tough to maintain.

He's always been a little slow but nothing like this. He just completely changed on the day I changed the sump/heater. The only differences I can think of are that the temp went from a slow always-changing 80-82 to a rapidly changing 80.8-81.3 on average, and the stuff growing in the tube that I just noticed.
  • #6
I think I can help with the tubes. This is how I keep mine clean; I use a Maxi-Jet 900 pump to add water from buckets back into the tanks when I do my weekly water changes, and I use the same pump to clean the tubes. I attach a tube to the pump in a bucket of distilled vinegar and water, submerge everything in the bucket and plug in the pump. I let it run for 30 minutes or so. When that's done I dump the vinegar water in the tub and put the bucket in the tub under the tap. With the pump still in the bucket I let the other end of the hose hang over into the tub and let the water from the tap go into the bucket while the pump is plugged in. I let the fresh water run through for another 30 minutes. All of my aquatic tubes are sparkling clean afterwords.

Even if you do not have a pump, you can do it the old fashioned way and siphon to get the water flowing through the tubes in a bucket.
  • #7
I don't think the algae would affect the fish, as sometimes that kind of algae grows in the tanks themselves, so unless its some dangerous type that I am unaware of I don't believe that the fish is in danger due to that.

Your right, if it is infact fungal or bacterial it would/could affect your other fish, but if this fish has been ill in the past his immune system could be a lot more susceptible to an infection. The other thought is that he could have a parasite..

How is he today? Any changes?
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  • #8
I cut a new tube to the same length just in case and replaced the one with the growth all over it. I'll have to try the vinegar trick Mamajin was talking about so I don't have to keep replacing tubes. It's certainly not coming off with just hot water.

Today he's probably a little worse. He's been spending most of his time on the bottom of the tank for about a week but today he's staying in one spot for a lot longer and he doesn't seem to react to almost anything. He would usually follow my finger but not today.

I tried giving him some frozen bloodworms for a change but he kept going back down to the bottom without going for it. Eventually he did grab it but with it half in his mouth he spazzed out and went down to the bottom. Then he sat there with it hanging out of his mouth for about 20 seconds before finally swallowing it.

He seems to dart up for air now and then immediately go back down. There's lots of plants he could sit on to stay near the surface but he doesn't seem to have the energy to look for a spot.

If he has a parasite does that eventually call for a full re-do on the whole tank system? Not sure how I would figure out that's what it is unless the other fish catch it later on.

I was thinking of putting him in a 10gal quarantine tank with fresh water but since the other fish are totally fine and he's so stressed out I'm not sure if it's a good idea.
  • #9
are you able to get a smaller tank or container even, and only half fill it with water so he doesn't have as far to go to the top of the water to breathe, raise the temp in there slowly cause that will boost his immune system and also feed food soaked in garlic juice. and add some conditioning salts only as much as recommended as it can burn fish and do worse.

All of these things are natural ways to try and boost the health of your fish.. also with the tank with lower water maybe add some tall-ish plants for him to rest on near the top.

Is any of this possible?
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  • #10
I'm prepping for putting him in a different tank. Just waiting for the water to age a bit longer while I decide. I have to wait for the pH swing to finish (when the CO2 leaves the fresh water).

I don't have any garlic juice, I could pick some up if it really makes a difference. I was thinking of not feeding him today though. He seems to be flipping out more, flying around his tank until he gets air and then landing at the bottom, once an hour or less. Even going crazy when he sinks to the bottom and hits it harder than he expected. I'm not even sure he would eat anymore, he's not coming over to the hole when I open it up. But he's been well-fed up to this point so hopefully he'll be ok without it right now.

The only way I can get a heated tank is if I use my 10gal water aging tank, half filled maybe. Biggest I have other than that is a 1gal and that's probably too small for my old 25W heaters and it's taller than it is long/wide. I don't have a sensor in the 10gal tank though so I'm not sure how well the heater is calibrated or what the temperature swings are like. It'll be tough to get it at the exact same temperature as the current tanks too. Working on it though while the water ages.

At this point I've hooked up an arduino controlled relay to my heater to manually turn it on and off based on the temperature my sensors are giving me. It should stay within 0.1F at this point, seems to be working so far. Hopefully that will help a little though I'm not sure temperature swings are the problem.

I could just crank up the heater in the current system and with the new program slowly turn up the min/max temperature values from the current 80.7/80.8 to 81.9/92.0 or maybe higher if bettas can handle that. Not sure if I should do that or get a second tank up to those temps.

Would completely fresh water be worth the shock of changing tanks? Last 10 gal water change was on June 2nd, should be pretty fresh still...

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