help, sick fish!

[zoezealand]

I have a 150L 3foot tank, with 5 zebra danios and 2 guppies, it has minimal fitration (approx 700L/hr with internal filters), and has 15% water changes every few days

One of my danios always had a tendancy to swim with his tail higher than his head, but this never got worse and I never thought anything of it, till the day before  yesterday, when I went down in the morning and he was floating at the top not really moving, breathing quite quickly. His stomach looked slightly bloated, every few minutes he would roll onto his side abit and have to swim to get back upright. he keeps his fins away from his body, there are no obivous marks or wounds.

ammonia posioning matched the symptoms, but the tank is very lightly stocked with water changes. So I thought it might be internal parasites.

I did a 40%water change, and treated with a half dose of 'white spot remedy' (I know he hasnt got ich, but I thought it might be useful for all parasites, it also says 'useful as a general aquarium disinfectant', it contains 0.85g/L malachite green, 98g/L formaldehyde)
A also added 4 tablespoons of aquarium salt, and raised the temp 2 degrees

after all that I noticed that my male guppy was hiding on the bottom behind a flower pot, hardly moving (I did not notice this before, but he may have been the same), my female guppy was hardly moving either, but she was not on the bottom as much as the male,
the danio appeared to have improved, he would swim down a bit, but as soon as he stopped swimming, he would quickly float again, he was a bit more active

I thought the guppies may be reacting to the meds, so I did another 40% water change,
minor improvement in the female

yesterday I did a 20% water change, the danio and guppies looked to be improving

today the danio was back at the top still breathing heavily and very boyant, he moves occasionally

the guppies were slightly worse (or back to the original level), another danio is now spending a lot of time resting at the bottom
I did a 1/3 dose of the white spot remedy, and 1 tablespoon salt

Is there something which could cause one fish to float and the rest to sink?

could they have a bad reaction to meds?

does the danio have parisites, or could it be something else?

does anyone have any ideas on treatment, which could cure the danio, and cure/ not adversly effect the rest?

I have another 10L tank spare, should I put the danio in it to treat? if so should I treat the rest with anything?

basically i have no idea what to do, any thoughts or comments would be great, I dont want to loose everyone

Thankyou in advance
Kathryn

[wrk21]

kathryn,
sounds like a swim bladder prob......and no theres not alot you can do about it....

[Paul]

yep I agree, swim bladder problem for sure. You could spend $20 on various treatments but you'll probably end up doing harm to your healthy fish and the sick one will probably die anyway. Just let him try to heal himself. otherwise.. you never really liked that fish anywayz right?

Yea i guess there isnt alot you can do if its swim bladder probs, Although i have been looking into fish surgery, Seems abit weird, and I personally wouldnt try it unless i knew it wasnt hurting the fish I.E knocking it out properly during it.

But i hope one day to be able to try something instead of just waiting for them to die.

anyway check this out - http://www.pbs.org/wgbh/nova/sciencenow/3214/04.html

not that i suggest home surgery.

[zoezealand]

thanks, that is half good news, at least it isnt contagous,

he has improved slightly, but still spends 60% percent of the time with his back out the water.

peas are supposed to be great for goldfish with swimbladder disorders, would it work for him? (I dont know how I'd get him to eat peas though)

wow, that fish surgey is amazing,
if it were a 30cm goldfish, then I might consider it, but I would never be able to operate on my 4cm danio!
it presents an interesting idea, the surgeons used stones to weigh the fish down, I wonder if it would work scaled down and externally,
I could picture a little cloth jacket, held in place by the fins, and put on under ansethetic. the jacket could have sand or pebbles sewn in the bottom, (I would only try this as a very last resort, it woud proberly stress the fish out a lot)

thanks heaps

[DeagonTheo]

I wouldnt worry about doing too many water changes with the amount fish you've got in that tank, maybe once per fortnight or even month, 15% is plenty.
Theo