2 Fish Died In 3 Days 3rd One Not Looking Good Any Ideas?

[sirichmond]

Hello,

On Sunday one of our female Dwarf Gourami's died of Dropsy, this morning Tuesday found one of our Male Mollies had died during the night no obviuos casue though may have died of stress only been in tank since Sunday afternoon and this evening after putting a few peas in for the plec noticed some strange behavior from one of our Rainbow fish, as I type this it has just passed away. Basically all of a sudden it started swimming upside down and its mouth was permanently open every now and again it would just fall to the bottom as if it was dead and then after say 30 seconds swim again and then drop to the bottom. There were no physical signs of any disease and went from being not very well to dead in about 10 minutes. Any ideas as we are getting a little worried about the fish. We are also treating the tank with Melafix as the Male Mollie which is now dead did have a start of cotton mouth. We did a water change yesterday and our stats done at 10.20pm tonight are:

Ammonia : 0
No2 : 0.1mg/l
No3 : 10mg/l
PH : 7.5

Only change to tank other than new Fish at wekend is we got a Co2 plant system which runs all the time and we switch on tank bubbles in the evening as advised by our LFS.

Tank is 200L and is stocked with:

3 Neon Tetras
3 dwarf Gouramis
4 Guppies
3 Platys
1 Gold Nugget Plec
3 Silver Mollies
2 Dalamtion Mollies
2 Rainbow Fish

Any advice would be more than welcomed and would be very grateful. Tank been running 8 weeks or so, fishless cycled.

Cheers
Simon

 

[backtotropical]

Hi Si,

The fact that you have detectable nitrite is an indication that something isn't right. It may indicate that you have had ammonia and nitrite spikes which the filter is just catching up with now.

How often have you been adding new fish? If you have so many fish dying, you shouldn't have added more fish at the weekend as this can only excaserbate the situation. You need to establish and deal with the problem before adding any more fish to the tank.

Have you been doing water tests regularly? If so, has there been any ammonia or nitrite showing?

Also, are you monitoring the level of CO2 in the water? Too much CO2 will basically suffocate your fish.

Cheers

BTT

 

[sirichmond]

Hi BTT,
After the cycle we got 5 fish then the following week another 5 missed a week then some more generally no more than 5-6 a week but not every week! Had not had the dying problem untill sunday thats the day we got the new fish! the same lfs as we always do they are a good one very rarely is there a dead fish in any of theire tanks.
What tst is it for CO2? however dont think there is a problem there as have a 205 Fluval filter (external) and 2 airstones?? also none of the fish seem to ever be gasping or hanging round the top.
Do water change once a week and treat water first its a 200ltr tank and always take a minimum of 40 - 50 ltrs out and disturb the sand before hand as we heard that the sand can hold posionus gasses if not disturbed now an again. Our Nitrite has always held ay 0.1?

Hope some of this helps BTT and thanks again