Mysterious Betta Death!?

[Noahsfish]

So Id had my betta for maybe about 3 months now. He was originally in a 20 gallon but about 3 weeks ago I moved him to the 10 since he was nipping my dalmation Molly. The 10 gallon is fully cycled with 6 harlequin rasboras, it's also planted. After I transferred him he's been completely fine..until today when I saw him lying on the ground. He then struggled to the surface for air, swimming very awkwardly. I assumed it was swim bladder disease so I thought I'd have more then a couple of hours. From the time I saw him 2 hours passed until I checked on him and found him not breathing. His coloration had gone from a deep red to a sickly palish yellow color....what could've causes this death??!? I'm starting to get freaked out because 4 days ago one of my corycats randomly died also....I do 25% water changes every 5 days and vacuum the sand with every wc...I use aqueon filters (I know..), and I put the fluval bio rings in a mesh bag in the filter also. I tested the water chemistry with my personal testing kit and my lfs. 10 gallon

0 nitrite
0nitrate
0ammonia
7.8 ph
120-180 gh.

20 gallon is similar.

 

[RCA]

Sorry for your loss Noahfish, it is a hard one to diagnose.
Did his behaviour change prior to becoming ill, other than what you have already stated? i.e. off his food, hiding etc?
 
A couple of thoughts:
 
When you say you vacum the substrate at every water change, are you cleaning the whole tanks substrate each time?
What is your substrate and how deep is it?
 
What do you have in your filter as media?
How do you clean your filter?
 
Do you use de-clorinator, and if so which brand?
Do you add any other additives to your aquarium?
 

Betta

 

[Noahsfish]

Sorry for your loss Noahfish, it is a hard one to diagnose.
Did his behaviour change prior to becoming ill, other than what you have already stated? i.e. off his food, hiding etc?
 
A couple of thoughts:
 
When you say you vacum the substrate at every water change, are you cleaning the whole tanks substrate each time?
What is your substrate and how deep is it?
 
What do you have in your filter as media?
How do you clean your filter?
 
Do you use de-clorinator, and if so which brand?



I do vacuum all of the substrate, I use just regular super naturals black sand. In the 10g I have 20 lbs in it so 2 inches. The aqueon filter has blue plastic which is supposed to retain bacteria, but I also use fluval bio rings. Once a month I change the cartridge and only clean the intake tube. I use seachem prime for my water and make sure it's at least room temperature. Before he died I saw him hiding under my driftwood..
Do you add any other additives to your aquarium?
 
Betta

 

[phoenixgsd]

how did you cycle the tank? i ask because you dont have any nitrates

 

[Noahsfish]

how did you cycle the tank? i ask because you dont have any nitrates

Sorry, I meant that they were all at healthy levels..

 

[RCA]

I do vacuum all of the substrate, I use just regular super naturals black sand. In the 10g I have 20 lbs in it so 2 inches. The aqueon filter has blue plastic which is supposed to retain bacteria, but I also use fluval bio rings. Once a month I change the cartridge and only clean the intake tube. I use seachem prime for my water and make sure it's at least room temperature. Before he died I saw him hiding under my driftwood..

From the information provided a few thoughts:
 
What is your reason for changing the cartridge monthly?  When you say blue plastic is it a sponge?  The best thing to do is to rinse this in water taken from your aquarium, and the same with the Fluval Bio rings.  I do not change my sponges unless I have had an outbreak of some sort or they are falling apart.
 
Prime is a good product so that is OK.
 
He would hide prior to passing away.
 
Did he look bloated at all?
 
What do you feed your fish?
 

how did you cycle the tank?...

 
Can you advise ala the above question please.
 
Sorry for all the questions but it can help pin-point what may have occurred.

 

[Noahsfish]

I'm not a 100%, but I believe the cartridge contains carbon and helps trap debris. The blue plastic is well, plastic. It has this rough poreous surface which I guess bacteria is supposed to live on. Where the water flows into the filter I have some fluval bio rings placed, which I never really clean. I can't really remember if he was bloated looking, but he definetly didn't look skinnier then he was before. I feed tetra tropical flakes as a staple, and I fed the betta betta pellets mostly. Once or twice a week I feed the whole tank with spirulina(?) brine shrimp or a mix of blood worms, daphnia, cyclops, etc. The betta also used to steal the corycats wafers, but those weren't available to him after he switched tanks.