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Fish all died -- tests seem OK

1432 Views 4 Replies 3 Participants Last post by  Agent13
Hi -- fairly noobish, and I'm at a loss for what went wrong. I've had a betta in a small bowl for 2 years, and decided she needed a new home. Picked up a 3.5 gallon fluval set-up, added rocks and a few live plants, a heater, and let it cycle for a few weeks. She was super happy.

My five year old wanted to give her some company, so did a bit of research on what could co-habitate with bettas, and decided on a dwarf african frog and some shrimp to keep things clean. Started first with the frog, and they got along great; even hung out on top of each other.

A week or so later we decided to add the shrimp. I picked up 2 and while there noticed the shop had a tiny half-bill (pinner ~3/4 inch) that the guy said shouldn't be an issue and didn't get any bigger. Here's where things went wrong.

I added the two shrimp and half-bill. Three days later, my betta was dead. then a shrimp about 4 days later. then the halfbill the next day. then a day after that (today), the other shrimp. I'm left with the frog (for now).

I tested the water after the betta died:
PH 7.5-7.6
Amonia: 1-2ppm
Nitrite: 0ppm
Nitrate: ~10ppm
temp: 78 deg

Then again after the first shrimp:
PH 7.5-7.6
Amonia: .25ppm
Nitrite: 0ppm
Nitrate: 0ppm
temp: 81 deg

The only other thing I can add:
- I've been feeding them daily, but I think the right amount.
- When adding the shrimp/halfbill, water level was down ~1 inch so I added the water from the bags they were in -- mistake?
- fluval says to change one of the two filter cartridges every two weeks; since these are hard to find I haven't done that yet, but assumed since the water was testing OK wasn't necessary yet -- mistake?
- last thing, the water just over the past few days has started to look greenish, I assume from the plants. Does that mean anything?

Any thoughts would be appreciated -- I'm really bummed, esp about the betta which we've had for so long, and hesitant to start over when I don't know what happened.
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unfortunately, a 3.5 gallon tank is far too small for more than a betta, and perhaps a few shrimp. 1-2 ppm of ammonia is EXTREMELY high, and quite poisonous, and would probably be the reason the betta died. Frogs produce a LOT of ammonia for such little bodies- mine lives with one snail in a 5 gallon tank. add another fish to that, and you've got them swimming in their own poison for sure.

Another part of your problem was probably that the tank was far from cycled, which you can see because your ammonia levels were not 0. If a small tank like that cycles with one fish, it would be able to support one fish. any tank that's cycled will have to catch up with each additional fish added, which is why many people only add one school, or even just a couple of fish to their tanks at a time, until levels are all caught up.

I think the biggest thing to know, for a person fairly new to fish keeping, is that pet stores are out to make money. they're going to try and sell you what they can. even 10 gallon tanks are small for a community, and that's the smallest i would suggest for what you had up there, and i don't particularly know much about half bills. a 3.5 gallon tank would really only suit a group of dwarf shrimp, one betta, or perhaps one african dwarf frog (and i know people who don't like frogs in less than 5 gallons).

For now I would suggest leaving the frog to himself in the 3.5 gallon tank. If you're interested in a community, investing in at least 10 gallons would start to give you options for a few smallish fish (and the frog if you chose to move it). of course the bigger you go, the more options you have :)

as for the filter cartridges, i believe most of the beneficial (nitrifying, ammonia converting) bacteria live in your filter media. changing the filter cartridge would ruin your cycle, since most of your very necessary bacteria would be removed. if your filter cartridges started falling apart, i would place a new one in the filter, leaving the other one for at least a month, then removing the old cartridge.

Good luck! Starting out in fish keeping can be kind of stressful, and I hope you take another shot at it :)
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thank djembekah -- I was going off my test kit, which said in a new set up amonia could briefly reach 4pm, so thought 1-2pm was obviously not zero but below that 4ppm level.

I get it now with adding one at a time until levels settle.

I checked the amonia again yesterday, and it read 0pm, and several days earlier 0.25ppm, but things keep (kept) dying. Could that just be from the stress several days earlier? everything else seems fine from what I can tell.
The stress was probably part of the problem, yes. when stress goes up, i believe immune systems go down, and make anything more susceptible to disease they may be carrying. definitely wouldn't add more to that small of a tank if I were you, but hopefully your remaining buddies do alright.
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only have one thing to add to what Bekah said. In fluval setups they are realy good about not telling you to toss the important media from the filter. Most likely they just recommended replacing the carbon bag..which is fine...but not particularly harmful to forget or not replace at all. However during a new set up the carbon probably will hep if it's fresh till the cycle is finished.
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