bluefins fading and dying

i collect natives here in central fl. i have a 10 gal tank with blue fin killies, and dwarf livebearers, the livebearers are fine, but the killies are dying off rapidly, i have a second tank using the same water with happy topminnows and mollies, nitrates, nitrite, and ammonia are between 0-.25, ph 8.4, same as my tapwater and their source water, i do weekly water changes, my tapwater has a filter that removes chlorine, i feed tetra flakes once daily, some of the fish had what appears to be tuberculitis, others distorted spines, some seemed to become thin, they do also seem to slowly lose color, others died looking pretty, ihave been using 2 small filters without carbon. i have bought some ph down and lowered to @8.0 and installed new carbon filters, any advice

A more diverse diet might help, including mosquito larvae, fresh-hatched brine shrimp, moina or daphnia, chopped live blackworms or freeze-dried blackworms, frozen bloodworms, cyclops, etc. Wild- caught bluefins usually need other foods besides flakes, especially during those first few weeks when they're recovering from collecting stress. Also, the tapwater filter might not be removing enough chlorine, so you might want to use Prime or similar dechlorinator just to be safe. "Fish tuberculosis" (Mycobacterium) is certainly possible too and fits the symtoms you describe. Killies are sensitive to it.

Edited by gerald, 28 June 2012 - 03:51 PM.

Are you electrocuting them?

Distorted spines does sound like mycobacterium marinum. Do you see the swordtail with the curved spine in this video?

I try to keep her out of the camera's view but she pops up every now and then, for example at 1:28. You'll recognize her when you see her. Are they curved like that?

Edited by EricaWieser, 28 June 2012 - 11:20 PM.

Just my first thoughts - What gerald said about the food. Wild caught fish have most likely never eaten a freeze-dried anything. They are used to live food or food that was alive very recently (fresh).

PH Down is gimmicky and long term is a waste of money. I would mix with rainwater or RO water. I like the cost of rainwater myself.

I don't trust those tapwater filters. Your's could be losing effectiveness and you might not realize it. My local water company has what I call "SuperChlorine" days where they will add unusually high amounts of chlorine on some random day (It's probably not random but it seems that way to me). I think it's intended to zap the system or something but on those days there's so much chlorine in the water it practically burns your nose when it comes out of the tap. I strongly suggest Prime or another high-quality chlorine/chloramine remover.

I agree about food.

Personally I've always enjoyed collecting far more than I had the capacity to keep, so I often would go out for live food rather than fish. If that's your idea of a good time there are lots of options that far south - bloodworms, mosquitos, daphnia, hellgramites, dragonflies and stoneflies (be careful to ID these; some may be endangered), and more. Mosquitos especially are readily cultured in a bucket as long as you're dilligent about removing them before they get too big.

They do well on frozen foods though if collecting isn't your idea of a good time.