What did your ammonia test show? Was it at zero? Also, what was a nitrite reading at? Red gills is often an indication of ammonia poisoning. Also, do you use any gravel? With no filter, I am wondering whether your potentially resetting your cycle with each water change as nitrifying bacteria usually lives on the filter and in gravel.

Another possibility is some sort of infection. Bulging eyes are commmonly knoen as pop-eye and are usually secondary infections. Did the fish show any other odd signs - fungus on mouth, fins looking frayed, off color, white spots on fin/body?

Let us know!

Karolina,I use no gravel but have been assuming beneficial bacteria are on the roots of water hyacinth and other plants? Had one test strip for ammonia and was fine. The vial of test water stayed light yellow. He was acting normal except after water change he didn't start making his bubble nest. He looked fine except didn't come to glass looking for food. Some of the plants I bring in from outside have alge on the that I don't rinse off so they can hunt for bugs. I don't understand cycling.
Thanks for your response, Sue

To answer your question, if you just added the other plants, there would not have been enough time for the bacteria to grow on them. As for the water hyacinth, I am sure some would grow there but I am unsure whether it would be enough for the water volume, plus each time you take the plants out and put new ones in, you completely redo the cycle (and a cycle can take 2-6 weeks on average).

Unfortunately, we might not find out what exactly happened to cause the sudden death. Might have been an infection, might have been ammonia poisoning, or might have been something on the newly added plants. However, fish with the correct water parameters and a cycled tank are significantly less likely to catch any infections and are much better able to fight off any foreign bodies.

Thus, let me attempt to explain cycling in hopes that it will stop the sudden death of fish:

Five steps in the water cycle
1. Ammonia enters the water either through fish waste, fish food, plant decay, etc.
2. Ammonia nitrifying bacteria grow. These turn ammonia into nitrITE.
3. At the presence of nitrITE, another group of bacteria grow that turn nitrITE into nitrATE (capitals added for emphasis to show they are two different things)
4. No bacteria exists in aquariums to take care of nitrATE. Nitrate is removed via plants (who then give off ammonia and thus the cycle starts again) or through water changes.

Thus, at the beginning of a cycle, you will see ammonia spike, after a few hours to days, ammonia will drop and nitrite will spike, then after some time, nitrite will spike and nitrate will spike. Eventually, enough bacteria will grow so that your ammonia and nitrite are at zero and only nitrate is found in the water.

Ammonia and Nitrite are toxic to fish even at small levels. Nitrate isn't as bad and levels that can be handled by fish depend on the type of fish.

Things to keep in mind - a water change does not necessarily bring everything back to zero. For example, my tap water tests positive for nitrates at 40 parts per million. Only way to completely go to zero is to use distilled water (and that is not recommended for beginners as you have to balance ph and add minerals back into the water).

Second thing to keep in mind is that your ammonia test quite possibly tested at zero because your water conditioners remove ammonia by binding with it for a time being. That is why you never test after a water change but wait a day or two to test.

So in your situation, I would get ammonia and nitrite/nitrate test strips. I would change the water completely again in case there was an infection in the tank and condition it as normally. After about two days, I would test with both the ammonia test strips and the nitrate/nitrite ones. If you are showing positive on either the ammonia or the nitrite then you know your tank is not cycled. At that point, it is your decision on how quickly you want to cycle - my guess would be that on plants, it is not easy for a lot of bacteria to be present and thus it would take awhile. At that point, I would also be aware that you cannot change out a large number of plants at the same time.

Otherwise, I would add gravel and cycle it that way. To cycle, the humane way is to either add a few drops of ammonia or to add a small amount of fish food every day. Eventually the bacteria will convert the ammonia from it to nitrite and then to nitrate. Only when your ammonia and nitrite test at zero, even after adding food recently, are you cycled. In a tank that size it should take about two weeks but could take as long as six depending on water parameters and water temperature. Adding products with active Bio Spira such as Tetra SafeStart with Bio-Spira bacteria has helped me speed along the process.

At that point I would consider it safe to add a fish, making sure to do regular water changes to get rid of nitrates (but not removing everything to clean etc).

As for your pond plants, I would make sure to wash and sterilize them before putting them in a tank. Bettas are tropical fish and thus not used to the insects and other pathogens they might encounter from our ponds. However, that is strictly an opinion as I do not have a pond that I bring plants in from.

Hopefully this helps! Let me know if I was unclear about anything!

Thanks again for responding and explaining Karolina. I purchased a 10 gal set-up with filter, gravel, already had the heater. I used that Safe start. He's in the new one now livin' large. I wanted to get him out of that five gallon ASAP, can't believe how grody it got with one fish after one week. I truly believe the death of my other had to do with the plants from the pond. Really bummed I did that.
Do you have an opinion about the best type of filter? This is a waterfall type that is causing a lot of water movement. I shut it off this a.m. And he frantically built a bubble nest. I turned it back on and his nest seemed to be anchored on pretty good to a plant. I can see how he wouldn't be able to build with the water movement. Is that water movement stressful to them and should I look for a more gentle filter? Thanks again, Sue

I am sure he will greatly enjoy his new home!

As for the water movement, what I do in my tanks to restrict it is raise the waterline up to the outflow of the filter. That way there is no waterfall and the force is minimal. In tanks that dislike large water movement I also position tall plants around the output - not close enough that water isnt circulating well into the filter but a few inches away so that the water current hits the tops of the plants and disperses thus creating a much weaker current in the tank. Let me know if that works!

I'm sorry your betta died. I love bettas and currently I own 2 of them. One, a female (pictured) and an elderly, feeble but healthy male.

First of all, you can keep a betta alone in a 2-1/2 gallon tank with no filter and a heater, he/she will be just fine.

Your betta could have been very mature and perhaps the water change may have caused something to make him sick. It has happened to my bettas in the past. Sounds like your betta had a condition like Popeye. Which is always fatal.

100% weekly water changes are OK, but sometimes I do a 20% water change once a week instead of 100% water change. I like it on the dirty side just for the sake of the beneficial bacteria and the 20% water change won't hurt the betta at all. Just as long as you don't overfeed your betta it shouldn't be a problem.

Also, I keep several betta water bottles (the bottles you can buy at your local pet store, Walmart, etc. specially made for bettas) filled up with tap water and let them age for a week for the water change. Then I add 1 drop of water conditioner, a little pinch of salt and 1 drop of Melafix and a few drops of Blackwater Extract to the 2-1/2 aquarium and my girl doesn't seem to mind.

Just go and get another betta, and invest in a 2-1/2 gallon tank. Trust me, one betta will be very content alone in this tank and you just need a heater.

Here is my girl. I've had well over a year now. She is a glowing testament of the care I give her.

{{gwi:379697}}

Real pretty fish, thanks for the pic. I thought any betta you buy in the store is just a year old? I would like to think he was elderly but it was something I did wrong most likely killed him. I only noticed the pop eyes after he was dead, looked normal that day then died that night. Not eating that day should have told me something was wrong. I have one remaining and he's loving his ten gallon tank with filter, heater etc. I'm very tempted to buy another 'cause now I have a 2 and two 5 gallon tanks with no one in them. I just love them but for now just one is fine.

Tammy, I am going to disagree with popeye always being fatal. It is relatively easy to treat if you know what caused it. Usually it is a secondary infection. Googling the condition will give you many treatments for what may have caused it.

Also, it wouldn't make sense for fish stores to sell elderly fish. Why would a fish hatchery keep a fish that has reached maturity for a long period of time? It would only cost them the expense in keeping it. Also, there is no way it could have sat in a fish store for months on end. No one goes around to change the water in those little cups in most stores so the fish would have died before it reached old age.

Here is a link that might be useful: Pop-eye in fish

Why aren't you using gravel? It will take up most of the detritus (fish poop, uneaten food, etc.) and the tank will stay clean longer. My bettas live in a gallon tank with gravel and some plants, and live 3 or 4 years. I don't use an air pump with them since they don't need it. I do 100% water changes when needed.

Stores don't sell elderly fish, they get them from the breeders when they are about 6 months old. It isn't in the hatchery's interest at all to keep them until they are old. Those little cups do get changed frequently in stores, or they'd get really nasty in a couple of days and their death rate would be much higher than it is.

Eahamel,
You are correct and I retract my statement about water changes. My local store seems to have new bettas in weekly but a little research shows some chains change the water three times a week. Thank you for educating me.

Eahamel, I wanted to answer your ? about not using gravel. I've had trouble reposting but seems to be working for me now. I was doing 100% water changes every week so it was easier for me to not use gravel. I didn't want to hide the debri I wanted to see it and clean it out. Karolina turned me on to much better ways of maintaining my tank and the little guy seems real happy and feisty in his 10 gal. with filter, heater and GRAVEL. No more 100% changes, just vacuuming off the bottom every few weeks and replacing with conditioned water. About 20% or so. Thanks for asking , hope this helps others, Sue

#BetaThanYou

I had a Betta who was thriving for about 6 mos. in a 5 gal. heated,filtered tank with sand and gravel.The only thing I can think of is I rinsed a new piece of driftwood and put it in. He died 3 days after. My pleco died a day later. Test strip said all was well with the water. It was artesian water without chlorine. I buy it for drinking. Never had a problem until last week. Any ideas?