Established Tank- Bigger Suddenly Fish Dying- Cloudy -

[Worried]

Request Help.


Tank size:
pH:6.8
ammonia: don't know
nitrite:0
nitrate:100
kH:0 - 3d
gH:10 -16d
tank temp:25'C

Fish Symptoms (include full description including lesion, color, location, fish behavior):Two stages
25cm Sharktage 1) redness around fin base and mouth.
Stage 2) Clouded eye then Eye 'exploded' outwards

All the other fish seem fine. We tried treating it ( see below) but the shark died. That evening there were four other dead fish that had previously exhibited no symptoms.

Volume and Frequency of water changes: 25-30% every two weeks

Chemical Additives or Media in your tank:
1x Fluval3plus underwater Filter
2x subaqua aerators
3 natural plants ( 2 of which we introduced after the shark started looking sickly to try and boost the water)
1 plastic log.Fluval Tronic Aquarium heater

Tank inhabitants:
25cm Shark (deceased)
1x Angel Fish (deceased)
2x Gurami
1x Catfish
2x platties
1x red barb



Recent additions to your tank (living or decoration):

Exposure to chemicals:

Digital photo (include if possible):

 

[tibby25731]

Your nitrate should not be that high! Do a big water change ASAP and test again. You wnat it to be at least below 50, a lot of people prefer their nitrate to be around 20!!!

 

[Schmill]

Surely a snap decision to do a big water change immeditately here is not right?

This could be a case of OTS could it not? Doing a massive water change will drastically change the water characteristics, and could put the remaining fish into shock. Although as you say those nitrates are quite high, they are not toxic at those levels, (unlike having an ammonia or nitrIte reading, when I would suggest immediate water changes).

My first question would be why don't you know your ammonia level? This is one (if not "THE") most important water quality reading for a tank and it is definitly needed.
Secondly I would advise perhaps a 20% water change now, and then repeated over the next few days to gradually bring that nitrAte level down. You should also test your tap water for nitrAte so that you know what level you can reasonably aim for, (and post the results of that test on this thread).

Finally it sounds like there is a bacterial infection in the tank. The shark you describe sounds like a case of 'pop-eye', which although bacterial, is generally caused by poor water conditions. If would be tempted to get some Interpet anti-bacterial medication to treat the tank with (following advice I myself have been given on these forums). You mentioned in your text that you had 'treated' the shark, and "(see below)" but then I couldn't see any mention of medication. What did you use?

If you can get back with those details mentioned above then I'm sure someone else or myself can try to help you further.

 

[Worried]

Surely a snap decision to do a big water change immeditately here is not right?


Finally it sounds like there is a bacterial infection in the tank. The shark you describe sounds like a case of 'pop-eye', which although bacterial, is generally caused by poor water conditions. If would be tempted to get some Interpet anti-bacterial medication to treat the tank with (following advice I myself have been given on these forums). You mentioned in your text that you had 'treated' the shark, and "(see below)" but then I couldn't see any mention of medication. What did you use?

If you can get back with those details mentioned above then I'm sure someone else or myself can try to help you further.

Thanks for the offer.
For somereason i got an error message half way through writing the post and somehow it ended up posting it before i finsihed it ( which is why there are two threads on this - i wasn't even aware that this one existed!)http/www.fishforums.net/index.php?showtopic=263428 for pictures too) but i've just copied the rest of the post in here:

Recent additions to your tank (living or decoration): 2 new waterplants in response to shark illness ( which may have introduced some tiny snails!- we've never had snails before)

Exposure to chemicals: Aquarium salt ( treatment appropriate to tank size)
1x treatment of Interpet Anti fungus and Fin Rot ( treatment appropriate to tank size)
1x treatment of Interpet general tonic.( which is listed as anti-bacterial)
(also use a compatable weekly cleaner and chlorine control when changing the water)

Grateful for all suggestions.