Betta Helps. :(

[4seasons]

ammonia: Between 0.50 & 0.75. (Im working on this.)
nitrite:0.25ppm

These 2 are a huge problem. Any nitrite or ammonia means your tank isn't cycled and you need a 70-90% water change with temperature matched dechlorinated water any time you get a reading of ammonia or nitrite. You can read up on fish in cycle here: http/www.fishforums.net/index.php?/topic/277264-beginners-resource-center/

 

[miapusscat]

I've had my fighter and his 6 neon tetra buddies in their tank for a month (I've had bettas for yrs) but it was set up and running for at least 3 before that - I also have a big cold water aquarium so I used the waste from my other filter (its 2 yrs old and gets rinsed in tank water when it needs it) to put on my new filter and let that bio nasty goodness help kick start the new cycle. It seems to be a fail safe method and has worked quite well - if you don't have access to it there is stuff you can buy to help the cycle start as it takes at least weeks if not longer (my local fish guys have told me) for it be running in a complete or productive manner. When my water levels were dodgy, I did 10% changes morning and night for a week - cleared up any problems I had. In my experience, the water it to blame for most things


I do think its normal for him to hide but watch the tetras! Mine were nipping at my poor baby's beautiful fins which led to him getting finrot and losing some of his tail. The place I go to for all advice (run in the shop like a mad woman yelling about my poor fish) tells me tetras can nip the fins when its dark so I had to separate them for a while to give my betta a rest but after a few hours he perked right up and the tetras are leaving him alone. I would advice Tetra Pond Medifin - I know its a pond medicine but it cures everything - seriously. Me and my family treat it like the Holy Grail! When my Interpet Anti Fungus and Finrot wasn't working for my betta, the Medifin did. It protects fish against stress as well. Its very potent - I only use 1ml at a time for my tank and it turns your water blue for a few hours but it has saved the lives of so many of my fish over the years - cold water, tropical and the koi bigger than my cat in our pond! Its a general tonic. My betta (after rescuing him from Pets at Home where he looked dead) has had swim bladder, finrot, refused to eat, laying on the sand and in tiny holes, cotton wool like growths on him, floating on his side and looking definitely dead - Medifin each time, don't feed them for a day or so (they'll be fine) and he's staring at me right now begging for more food. But fix your water first, I test mine everyday like a paranoid crazy woman.

Also, overfeeding can seriously mess your water quickly - how often are you feeding them?

 

[miapusscat]

Also, I had my bettas yrs ago at 26/27 degrees thinking it was the perfect temp. but they when downhill fast. It was suggested to me that I lower the temp to 23/24 and all my bettas and tetra have been fine ever since. In fact, they seem to thrive on it.

Hope your fish gets better, he's a lovely fish btw from the picture you posted. Mine's a blue veiltail!

 

[phoenixgsd]

if you don't have access to it there is stuff you can buy to help the cycle start as it takes at least weeks if not longer (my local fish guys have told me) for it be running in a complete or productive manner.

it has not been proven that these products work, save your money, plain old water changes are your best freind, unless as said, you can get some media to kick start your cycle