Old Fish.....how Much Is Coincidence?

[Chaz]

I have had 4 realitivly old fish die in the space of 2 weeks, 2 rosy barbs, 1 white tipped tetra and a guppy. None of them have had any obvious symptoms and they are all around 2 years old . I'm wondering if i can consider these deaths as natural or suspicious. I have added the normal dosage of melafix and also done a water change after the first death.

Other things that happened: My juwel filter failed and they didn't have the 600lh filter in stock for 4 weeks (for my 180l tank) so i bought the 1000lh one ( I can take it back if I have to, as i had to put the old prop in as the new one was hitting against the sides of the casing). is this going to be a problem or a cause for the fish to die?

Also this morning for the fist time ever most fish were at the surface gasping for air, I then put the aerator in and it solved the problem 2o Min's later. Is this caused by an increased filter flow or because i had dramatically halved my live plant population in the water change 2 days before?

Thanks all that reply
Chaz
o and water stats are fine pH 7.3

 

[scooterchick]

Juts to clarify...did you have the fish for 2 years or do you know for a fact they were 2 years old? Perhaps they were older? I don't think 2 is particularly elderly for the fish you describe, perhaps middle aged but not pensionable. However, old enough for their immune systems to perhaps be a bit down and things like the filter failing might have a allowed a little infection to set in. However displaying no symptoms does sound like natural causes, maybe heart failure or something.

I wouldn't hav e thought an increased filter flow would affect the oxygen in the water, so must have been the plants. When you've ruled out everything else whatever you're left with must be the answer!

Do you have any stats for amonia etc? Alos, how big is the tank adn what is the stocking?

 

[Chaz]

Yes I have had the fish for 2 years, and I bought the the rosy barbs when they were not quite middle aged, white tipped tetras the same but the guppys were about 1 and a half years old when I got them off a friend (I had them for about 2 years before they died)
The tank is 180 leters and In it currently are
2 silver sharks (ready to be moved to a biger tank when they get too big)
3 amano shrimps
3 gold sucking loaches
8 cardinal tetras
3 white tipped tetras
3 corys
3 guppys
1 molly

Water stats: Nitrite 0 Nitrate 0 Amonia 0 pH 7.3 but hard water (no problem in past)

Charlie

 

[shelaghfishface]

i think,, and thats pretty sure think that you should have a nitrate of more than 0, but dont know what it means if you dont, maybe PM scooter chick

 

[Chaz]

Sorry, too used to reading 0's nitrate is 5.5

 

[Frasier]

Tank size sounds fine. Is there any debris at all on the bottom of the tank? Even if there is a little bit on the bottom as i have found out in the past this can reduce oxygen levels.

 

[Chaz]

A little bit but not so much as I did a water change 2 days ago with gravel vacuum

 

[Frasier]

When you had the more powerful filter attached were the fish having to swim more frantically than normal to compete against the current? Please don't take these comments personally but i'm trying to think of all the options.

 

[Chaz]

It's fine thx for the help.... Anyway the fish don't seem to be fining frantically but they definitely are swimming more and the cardinal tetras seem to be swept along more than other fish eg molly but the tetras have been fine so far. Do you think I should order the 6oolh pump off the Internet and return the 100lh one just in case?

 

[Frasier]

It might help. I presume there is no way you can turn down the flow of water as they say you can never over filter a tank but the flow of water could be the problem. How about adding more plants such as amazon sword to help disperse the flow of water before changing the filter?

 

[Chaz]

Thats a good idea, If i angle the flow into the glass back and the put some of my plants around it then it would disperce the flow, thanks so I have done that now and the tetras have come out abit, so I will keep the air stone in for a couple of weeks until my plants have growen again and I will see how the fish are tommorow.
Thanks evreyone for your help