Problem In Tank?

[katykaye]

Hello all

This week I have lost 3 fish. None showed any signs of distress or illness previously. My water stats are good, the tank is clean (and clear of the recent algae problems I had before christmas) A tiger barb has disappeared without trace and two cory dorys have simply laid on their sides and died

Just before christmas I changed the gravel to sand and added a new external filter (fluval 205) could either of these things be causing me problems?

Water stats today
PH 7.8
Amonia 0
NitrIte 0
Nitrate 5
Temp 76

30% water change weekly

 

[8inary]

when you changed the filter over, did you leave the old one in place whilst the new one cycled/matured?

 

[cowbla1]

When you changed over the new filter you need to leave the old one until the new one is cycled. But if you did keep it, maybe the sand could have gotten stuck in there gills but i have never used sand so don't think thats the problem i might be wrong.

 

[katykaye]

when you changed the filter over, did you leave the old one in place whilst the new one cycled/matured?

Yes - I ran them together for a week, and then I transferred some of the old media into the new filter too.

 

[cowbla1]

But you took it off? You should put that filter back on if you did. A week even with added media still would not be enough.

 

[katykaye]

But you took it off? You should put that filter back on if you did. A week even with added media still would not be enough.

its a bit late now I haven't got it anymore. I was advised that I could run the new filter on its own from day one if I transferred the media to it from my old filter? I thought running them together for a week and then transferring media too that it would be fine. My water stats since then haven't changed at all.

 

[8inary]

not sure if that is the issue, is your water milky? that would be a big sign that the filter hasnt matured/cycled.

 

[katykaye]

not sure if that is the issue, is your water milky? that would be a big sign that the filter hasnt matured/cycled.

No the water is clear and the fish and plants look healthy.

 

[pippoodle]

you could have had a spike of ammonia and nitrites when you removed the other filter

is this the fist time you've tested the water since the change?
in future run the old and new filters together for 4 weeks so the bacteria has time to build up in the new filter

corys are very sensitive to nitrites and ammonia and the slightest amount will cause them to croak

you are heavilly stocked for a 125 litre tank (approx 47 inches of adult fish excluding the corys) i would recommend doing 50% water changes and feeding every other day to make sure you dont get any ammonia spikes

good luck Sarah x

 

[pippoodle]

how are you doing today ?

 

[loraxchick]

What model was your old filter? And did you use all the media from your old filter in the new filter..or did you just use "some" of the media from your old filter???