Chronic Swimbladder

Hi,

I Have a goldfish with chronic swimbladder and i don't know what to do.

the fish was sold to me as a pearlscale but it is obviously not, it looks like a regular fantail. he loses control of his boyency (floats unless he is disturbed) around 1 or 2 in the afternoon and cannot regain full control until well into the night (about 4am). this happens daily. it occurred to me that it must be his food so to combat the problem, i cut up all the pellets, soak them until they sink and then squeeze them to remove any air still trapped inside. still, the problem persists. i have also made special gelfood that contain only peas and sardines. still, the problem persists. The fantail floats less on days that i do not feed him.

My levels are all in what is said to be the ideal range. i have three other goldfish in the tank who share the same water and diet and they have never had even a slight case of swimbladder disease.

does anybody know what the problem could be? if he IS just prone to swimbladder disease, is there anything i can do for him?

Thanks

i have tried both the starving and the feeding of peas.

This problem has been on-going for about a month and a half.
How would i know if it is a bacterial infection or damage to the swimbladder?
Could this be fatal?

i have never starved them for more than 2 days. Coincidentaly, i am leaving tomorrow for a camping trip for 4 days so i think i'll try it then .

My tank has an annoying 5-day cycle in order to keep everything in check.

here are my parameters:

At the beginning of the 5-day cycle:

Ammonia - 0 mg/l
Nitrite - <0.3 mg/l
Nitrate - 10 mg/l
GH - 8
KH - 5
PH - 8
CO2 - 1.6

At the end of the 5-day cycle:


Ammonia - 0 mg/l
Nitrite - <0.3 mg/l
Nitrate - 30 mg/l
GH - 9
KH - 5
PH - 8
CO2 - 1.6

By cycle i mean the frequency of water changes. instead of seven days, i change the water every 5 days. this is to keep my nitrates below 40.

(day-1 nitrates are at their lowest and day-5 at their highest.)

the lowest point on the water tester that i use for nitrites is <0.3 mg/l
and yes, this is what it always shows.

from what i understand, these perameters are very close to ideal. am i mistaken?

i would like to post a picture of my tank with all my fish. can anyone tell me how??