Losing About Two Fish Per Week - Why?

[corradophil]

Help, I don't want to loose any more fish.

All other fish appear healthy and active.

Tank size: 125 litres
pH: 7.8
ammonia: 0
nitrite: 0
nitrate: 40
kH: Unknown
gH: Unknown
tank temp: 25 Deg C

Fish Symptoms (include full description including lesion, color, location, fish behavior):

Over the last few weeks I have lost 3 fish;

1 Boesemani Rainbow - the first to die, I came home from work to find him dead, floating upside down at the bottom of the tank, I could see no sign of damage or change physically. I carried out a water change as a precaution once he was removed.

1 Harlequin Rasbora - Around 10 days later this fish lost it's colour, became very pale and was swimming out of control, and struggling to keep the right way up, within an hour noticing the symptoms he was dead. He died within 1 hour of switching tank lights on.

1 Panda Cory - Approximately 1 week after losing the Harlequin, last night 1 of my 6 Panda Cories had identical symptoms, to the Harlequin and died. Again he died within 1 hour of switching tank lights on.


Volume and Frequency of water changes: 30 litres once per week. Water always treated with declorinator

Chemical Additives or Media in your tank: None

Tank inhabitants after deaths:

6No. Harlequin Rasbora
5No. Black Neon
5No. Panda Cory
9No. Cardinal Tetra
3No. Coolie Loach
3No. Zebra Loach
1No. Ancistrus ranunculus
1No. Dwarf Rainbowfish

Recent additions to your tank (living or decoration):

Within the last week CO2 cannister, DIY using 2 litre bottle with 1 pint sugar, 1 pint water and 1/2 tsp yeast. 2 fish were lost before this was added.

One week ago 2 Panda Cory and 1 Ancistrus Ranunculus. 1 of the new Pandas is the one which died.

Exposure to chemicals: None, I was using Interpet No 2 Floraboost, but have stopped temporarily to make sure its not that.

 

[MartinD]

Hi,

I would suggest a water change, a big one. Your nitrate levels are way too high. Mine are always hovering around 5ppm but you're at 40.
You need to get that down straight away.

As well as the water change, increase aeration in the tank.
I'm no expert, but it also seems as though your tank is over stocked - what's the water hardness?
Temperature seems a little on the low side, but I wouldn't increase it just now - warmer water reduces oxygen in the tank.

 

[corradophil]

Hi,

I would suggest a water change, a big one. Your nitrate levels are way too high. Mine are always hovering around 5ppm but you're at 40.
You need to get that down straight away.

As well as the water change, increase aeration in the tank.
I'm no expert, but it also seems as though your tank is over stocked - what's the water hardness?

I'll do some more reading up on Nitrate, I was under the impression that 40ppm was acceptable, my tap water is around 30ppm, so its hard to get this down.

I'll try more aeration. I can turn the output of the filter to produce more surface aggitation.

 

[rocknurworld2006]

Hi,

I would suggest a water change, a big one. Your nitrate levels are way too high. Mine are always hovering around 5ppm but you're at 40.
You need to get that down straight away.

As well as the water change, increase aeration in the tank.
I'm no expert, but it also seems as though your tank is over stocked - what's the water hardness?

I'll do some more reading up on Nitrate, I was under the impression that 40ppm was acceptable, my tap water is around 30ppm, so its hard to get this down.

I'll try more aeration. I can turn the output of the filter to produce more surface aggitation.

if reading is 30 from tap that should be ok then

more surface agitation would be fine!

dont let temp drop anymore 25-26 degrees is ideal

 

[MartinD]

I'll do some more reading up on Nitrate, I was under the impression that 40ppm was acceptable, my tap water is around 30ppm, so its hard to get this down.

I'll try more aeration. I can turn the output of the filter to produce more surface aggitation.

Where do you live to have water coming out of the tap at 30ppm?!?!

And yeah, increase water agitation to get more oxygen in there.

Are they more placid/non-moving at any particular time of the day?

 

[corradophil]

I think I'll try another thermometer to double check temp. To achieve a higher temp I'll need a new heater as the one in there at the moment is set to maximum. I think the thermometer is fine, its the only one I've had, and I've experienced no problems like this before, but no harm in checking.

I live in Essex.

They seem quite slow early in the morning when I get up, but when I open the curtains they become more lively, certainly within 10 mins they're active.

 

[MartinD]

Try checking your levels in the morning before lights on or curtains open then check again at night.

Couple of things to think of:

At night, there's little light and if you've got a planted tank then photosynthesis takes place and the plants start using up
the oxygen in the tank. If you don't have enough oxygen, then the fish start to suffer. This can sometimes explain why they
can be lethargic in the morning before lights are on etc.

Is your PH steady? Again, check it first thing in the morning before lights on then in the evening. If there's a difference of anything
more than around .5 then you have water hardness issues (KH). I'd suggest getting some limestone in there to help stabilise the PH.

You might want to invest in a more powerful heater too. If the heater is on maximum and it's only getting to 25 degrees, then it's going to
have problems keeping the temperature. You really want a more powerful heater that will be able to keep the temperature at a constant.

 

[corradophil]

I'll test the water tomorrow morning when I get up, and turn the pump output tube more towards the surface to put more oxygen into the water.

I have noticed the PH is a little higher (approx 0.3) now than it was a month or so ago.

I want to add more rock anyway, so I'll make sure I get Limestone.

The water temp never seems to fluctuate, and comes back up within an hour or two after water changes, but I do keep a close eye on the temporature.

Thanks for your suggestions

 

[rocknurworld2006]

dont add limestone as it will bring your ph up, if your ph is already 7.8 then you dont want it any higher amd it is already too high for the fish you have anyway

temp will fluctuate a bit anyway when doing water changes but still invest in better heater.

 

[corradophil]

Yeah, to be expected that the temp will fluctuate with water changes, I was just trying to highlight that the thermometer reacts to temp change quickly and the heater is holding the temp at a steady level. I will however look into alternate heaters.

I'll hold off on the Limestone then. First off, I'll increase the water aggitation as soon as I get home this evening.

 

[corradophil]

I got home on Friday, and adjusted the position of the pump output to give more surface agitation. All fish appeared healthy.

I also carried out a water change, and sorted the heater issue. The tank is now at around 25-26 deg C.

Saturday, all fish ok in the morning/afternoon. I went out for a couple of hours, then returned at 7.30pm to find a pale, dead Harlequin!!! Straight away I removed him from the tank.

Since then. no more problems, but that seems to be a patern, everything appears fine, then one fish will develop the symptoms described above and die.

 

[corradophil]

Up untill last night all the fish have been fine, all active and looking healthy.

I went out for the evening, when I returned home one of the Panda Cories was dead, he looked absolutely normal - no damage, no discolouration, but dead.

I really don't want to loose any more, but just do'nt know what is causing these sudden deaths, one at a time.

 

[rocknurworld2006]

what are your water parameters ph,ammonia,nitrite,nitrate as of today???

 

[corradophil]

I'm at work at the moment, so cannot test, I'll try and get results tonight and post tomorrow. Unfortunately I have a really busy night as someone is retiring from work today and we're all getting taken out for a meal.

 

[shang hi]

I would suggest a water change, a big one. Your nitrate levels are way too high. Mine are always hovering around 5ppm but you're at 40.
You need to get that down straight away.

40PPM nitrate is not overly bad, i have 30PPM on average with a fair amount of stocking and feeding a good amount of food. most fish are good in water with less than 50PPm with no ill effects, and even up to 80PPM wont do any perminant harm.
some fishkeepers have 40PPM coming out their tap with no ill effects to the fish.