What's killing my bettas?

[gbose]

I just set up a new 3G tank for a betta, cycled it and installed a fish. It seemed fine the first day, then very lethargic and died on day 2. I thought there was something wrong with the fish, did a 50% water change and got a new one -- which was dead the next morning ...

It's a brand-new 3G 'Picotope' tank, filled with dechlorinated water and cycled. Small filter (no-name, came with tank), lighting unit (came with tank). I added a heater -- initially a Marineland 10W which didn't keep the water very warm; after my first fish died, I replaced it with a 25W Top Fin adjustable, which holds the temperature at 80F. This didn't help the second fish. Gravel is 'Estes', bought from a reputable aquarium store and lightly rinsed. I have a piece of Mopani wood, soaked for 2 days. Plants are Ambulia and Anubia, replanted from my main tank....also some Christmas Moss, bought online, attached to the Mopani wood.

The only clue I have is that there was some foam on the water at the filter outlet. I attributed this to Seachem (Flourish & Excel) that I added (a few drops only) for the plants. But I'm wondering if there's something that got into the water.....

I've rinsed out the gravel again (it's been soaking overnight, as has the wood and plants). I've rinsed out the tank and filter and am going to start cycling the tank again.

Does anyone have ideas about what happened and how to stop it from happening again?

GB

[Kethlas]

Well...bettas are labyrinth fish, which, briefly, means that they have a organ that allows them to breath oxygen - air, like we do - directly, instead of using gills like most fish.

Seachem Flourish and Excel, while great for plants, adds CO2 to your water. It's possible your poor bettas found it hard to breath, and thus, suffocated. They say it's safe for fish when used as directed, but I'm not sure if they take consideration for labyrinth fish. They should be, but they may not.

It's a quick answer based purely on first instinct, and there's a good chance it could be something else. I'm going to look around a bit more on Flourish & Excel before I say that's the definite cause.

[Creat]

I use flourish and excel in all my planted betta tanks and never caused any problems I feel that the issue may lie with the tank not actually cycling I suggest getting a test kit and doing it again. Monitor your cycles adding fish might have produced more ammonia then the bacteria can convert.

[Oldfishlady]

Sounds like a contaminated tank...fish shouldn't die that fast if they are healthy to start or it could be an acclimation issue and pH and/or nitrate shock..

Brand new tank..correct?
How did you cycle it and what are the water pram numbers-what kind of testing products are you using?

How did you clean everything and did you use anything to clean the tank and/or items in the tank
Check the expiration dates on the dechloranator
How did you acclimate the fish

Test your source water ammonia, nitrite, nitrate, pH-re-test the pH again in 24h from a fresh glass of water that has sat for 24h to get an accurate pH-it needs 24h to de-gas to get an accurate reading
Add the dechlorinater and test the water again and then test the tank water and compare all of these numbers and post

Before you add the next Betta....test these numbers and you will also want to test the pet shop water number so we can compare them with your source water-so you can acclimate the fish properly

[gbose]

Thanks, all! Appreciate your suggestions..

Kethlas -- yes, my number 1 suspect is the Flourish & Excel. I've rinsed out my tank and won't be using those again....

Creat -- yes, I think I had a mini-cycle after adding fish & 2 RCS Shrimp. But the ammonia never even reached 0.25PPM; surely not poisonous so soon...? I added my second Betta after a 50% water change -- surely should have kept it OK for a few days...?

OFL -- yes, brand new tank, rinsed under tap water. Gravel, also under tap water. Cleaned only with water rinse and clean aquarium scrubber -- no soap or other cleansers... Water/cycle tests using liquid test kits from API and Tetra. De-chlorinator is Tetra Aquasafe, exp date 07/13. I tested my tank after water change but before adding second Betta. Ammonia 0, Nitrite 0, Nitrate < 12.5PPM. I understand the numbers could have crept up, but the fish died within hours. I suspect you may be right re: PH, etc. being different from shop source. But I've bought all my fish from the same shop (Fintastic) and had only 2 casualties before -- both bumblebee platies.

I use the same tap water and de-chlorinator for my main tank (neons, platies, 1 guppy, 1 pleco) and my QT (now full of baby guppies, long story) and I haven't seen any problems. I thought Bettas were said to be hardy fish...?

OFL, I'll check my water, as you suggest and post results. BUt I keep suspecting something contaminated my water..... Hoping my most recent rinse-out will solve the problem...

Is there any way the Mopani wood could have caused the issue? I got it from LFS, so believe it should be OK... or the gravel...?

GB

[Creat]

I wouldnt stop using Excel and Flourish its up to you but they are the best plant supplements on the market at least to me and shouldnt do anything to your fish since I used them with tanks that house very delicate fish. And it might have been nitrite that spiked with is more toxic in smaller doses then ammonia. It also might have been the fish :/ but thats unnatural but does happen sometimes.

[baylee767]

If your cycling fishless and the ammonia never got above .25, it never cycled.

With the fishless cycle the ammonia will reach 3-5 PPM ideally, than the nitrites will spike and go down, then the nitrates.

Not exactly sure what's wrong with your tank /=

[gbose]

Thanks!

Creat, yes I use Flourish & Excel in my main tank and QT, with no bad effects. But I'm thinking something poisonous got into my tank.... so I plan to limit what I put in. I didn't test for a nitrite spike, but all parameters were OK the day before I put in the fish.....I'll monitor this going forward.

Baylee -- you're right, but I cycled the tank before putting in the fish. Think I got a mini-cycle after I added 1 betta plus 2 RCS shrimp.

Thanks for ideas!

GB