Help me not be serial fish killer.

January 8, 2011 2:27 PM

My Christmas present of a betta fish just died. What did I do wrong?

I read the previous answers about care and looked at some great websites, but I am still wondering what I did wrong, if anything.

The betta fish was in a little cup, moved him to a 1/2 gallon tank (for one week), then to a 2 gallon tank. The 2 gallon tank's water was conditioned. I live in an area where the temperature does not go below 70 and is usually 75-88 degrees all year round.

I read not to put a heater in a tank under 5 gallons, so the tank was unheated. I am assuming the water temperature and quality was ok.

I fed the fish 5 little betta pellets a day. He had a cave to hide in and some fake plants. I was about to get him some mosquito larvae, but then he died!

I have had large fresh-water aquariums for many years, fish die but most live for years. Many of my fish were quite elderly when they died. I pretty much know how to take care of a filtered fresh-water aquarium.

We have betta fish at work, one is 2 years old, one is 1 years old. They live in 1/2 gallon tanks and do fine. The building is kind of cold, about 70 degrees, 24 hours a day. They make bubble nests all day, and are active and friendly. I treated this one like we do the ones at work.

Any suggestions? I will probably be getting a new fish. My husband feels sorry for them living in the little cups at the pet store and wants to liberate one.

All this worry over a little fish!!

posted by fifilaru to Sports, Hobbies, & Recreation (10 answers total)

How often did you change the water? The beta fish in your office probably have their water changed every few days.

Even if you have water conditioner in your tank, you need to change at least 80% of the water every few days when you first put a fish into a tank (google fish tank water cycling if you wish to geek out and learn more). If you don't have a filter in the tank, and it's 5 gallons, I would still change at least 25% of the water once a week.

Also, the idea to not put a heater into a tank under 5 gallons is baloney. Just don't get a super high powered heater. You want a small Hydor THEO heater (they don't break if you leave them on out of the water) or a Hydor mini for 2-5 gallon tanks.

Finally, for beta fish, you need to have silk plants not plastic ones. Plastic will rip their fins and cause them to get very sick.
posted by lyra4 at 2:35 PM on January 8, 2011 [1 favorite]

Clarification:

If you don't have a filter in the tank, and it's 5 gallons, I would still change at least 25% of the water once a week AFTER the first few weeks once your tank is well established. Frequent water changes when you first get the fish though!
posted by lyra4 at 2:36 PM on January 8, 2011 [1 favorite]

I have a 2.5 gallon with the smallest possible heater and filter. On the other hand, I just turned around and looked as I was about to type "and he seems happy with that" and he was dead. So, uh...it's hard to say.

There's really no telling how old they are when you get them at the store, or what condition they are in, or whether there's something funky in your water. One thing to be very careful of is conditioning chemicals - they're often graded for a tiny amount for 10 or 20 gallons, so make sure you're not overdosing on that.

Farewell, Captain Jack.
posted by Lyn Never at 3:11 PM on January 8, 2011 [18 favorites]

I remember reading that the main cause of failure to thrive in betas is lack of live food.
posted by jgirl at 3:18 PM on January 8, 2011

Did you actually see your fish eat the pellets? I used to have several bettas and they refused to eat pellet food. They would mouth the pellets and then spit them out. The mosquito larvae, however, they loved.
posted by keep it under cover at 9:24 PM on January 8, 2011

I've had terrible luck with the bettas you get at the pet store, especially those big box stores which shall go unnamed. They have had difficult lives by the time you get them. And the sell-through rate is poor, so they can be years old and you'd never know.

Breeding is also a factor. They can have any number of hereditary problems and susceptibility to disease.

It sounds to me like you did everything right. Technically bettas prefer warmer temperatures, but as you've seen, they can do alright at room temperature.

You don't specify, but my guess is that he never really perked up after being brought home. My guess is that you just got a bad one. It happens.

The best way to replace him is to buy one from a breeder (they can be found online), or at least to buy one from a reputable local fish store. Not a pet store that also sells fish, but a proper aquarium store. They will have taken far better care of their fishies than a big box store would have.
posted by ErikaB at 9:38 PM on January 8, 2011

Bettas are mysterious. I had a betta that honest to god appeared to stop eating 4 months before he actually died (at age 3, so not particularly young). I would put a pellet/larvae in the water, and 90% of the time he wouldn't eat it. I thought sure he was a goner, but he kept on swimming. It was actually a real shock when he finally did die.

My point: who knows? It sounds like everything should have been good. He probably wasn't healthy to begin with.
posted by geegollygosh at 10:14 PM on January 8, 2011

Seconding that I've never had success with betta fish bought at Walmart or the like - I've had slightly more luck with dedicated pet stores like Petsmart, but I agree with ErikaB that a fish store or a betta breeder is the best source.
posted by muddgirl at 8:57 AM on January 9, 2011

I can't help, but I just wanted to commiserate with you and Lyn Never. I read your question last night and within the hour my heretofore healthy beautiful blue-and-purple betta was nose-down on the bottom of the tank.

I do agree though that sometimes it really isn't a case of you doing anything wrong. I've had new fish die overnight and when we take a water sample to the fish shop for them to analyse they're as puzzled as we are about what happened. It's just bad luck sometimes.

(I'd put a heater in a tank that size, personally, but it gets much colder where I am, so you might want to ignore that. :o) )
posted by raspberry-ripple at 10:36 AM on January 9, 2011

I also think 5 pellets a day sounds like overfeeding. 1 or 2 pellets a day was more than enough for my old betta fish, and I fed the little guy only 6 days a week. As a rule of thumb, try to underfeed rather than overfeed bettas. They are always hungry and like most fish will eat as much as you give them.

Second probably because of all the domestication and inbreeding (wild bettas are drab, and do not really resemble their brightly colored pet store cousins), bettas are prone to constipation from overfeeding. Check for regular fish poo at the bottom of your tank.

And general advice, keep the water as clean as you can. You can use a turkey baster to remove fish poo (you can use this as plant fertilizer btw) which prevents the waste from breaking down into ammonia, which reduces the water quality. There are also some preventative things you can add to the water to keep your fish healthy, like adding small amounts of aquarium salt (1 teaspoon of aquarium salt per 2 1/2 Gal of water according to here) and stresscoat.

I like to recommend this page for a great rundown on basics of betta care. It's not written in the most professional style, but it's done by a longtime betta breeder who really knows their stuff.
posted by everyday_naturalist at 10:52 PM on January 9, 2011