My Fish Have Died?

[chris301up]

I have been keeping tropical fish for many years and, generally without problems.
 
However, over the past week or so, all of my Swordtails have hidden themselves under the rocks and have died.
 
I am now thinking of selling up but before I do just thought I ask to see if anyone knows why this situation may have occurred?
 
I have not done anything different. My water is clear and changed weekly, and my other fish are fine.
 
Totally confused!!!!
 
 

 

[attibones]

Can we get stats?
 
Tank size, filter, temp, ammonia, nitrite, nitrate, tank mates, percentage of water changed? How many fish were in this tank before they started dying off?

 

[chris301up]

Right. The tank is a Jewel Vision 180 with a Fluval 205 external filter and temperature setting of around 74 degrees.
 
I haven't got the ammonia, nitrate and nitrite figures to hand now, as I discarded these about a week ago when changing the water, but I remember they were all at acceptable levels. Obviously I plan to check these again as soon as I can,
 
I usually change between 25% & 50% of the water. I never use additives to reduce chlorine levels, but get the water ready in clean buckets about 48 hours before changing and, whenever possible, leave to warm to room temperature.
 
My stocks are a little depleted at present so there were only 5 x Swordtails - 1 x Red Tail Shark - 1 x Neon Tetra and 1 x Otto. Not much for this size tank?

 

[attibones]

First, I see issues with your stocking. Red tail sharks are aggressive. Very aggressive. This could be an issue with your swords. Also, they are much too large for a tank of this size. I'd rehome him immediately. Tetras and ottos are both schooling fish so you need more of these.
 
Do you do water testing with liquid kits or with dip sticks?
 
I'm not positive, but I'm pretty sure that even sitting water out, while it does evaporate the chlorine, does nothing for chloramine. You also could do to bump your heater a little higher.
 
EDIT: I was thinking about red tail catfish for the size, but the aggression factor still remains.

 

[chris301up]

I agree about the stocking issues and was going to restock but have now decided to sell the aquarium,
 
I have had Red Tail Sharks for many years and have never found them to be too aggressive, but can understand your reasoning
 
I use liquid kits for testing which I have found more than adequate for my needs
 
Why, after many years, has this situation suddenly reared it's ugly head?

 

[KirkyArcher]

I've also never had aggression issues with RTBS when following the basic guidelines of keeping specimens singularly and avoiding similar shaped species and think 45+ us gallons is adequate for homing one fish. I also don't believe stocking issues could be an reason for fish deaths in this instance. I know of at least two people who have gone for years without adding water conditioners and just fill direct to tank, and have no issues for long periods then all of a sudden unexplained fish deaths occur and all water tests NH3 NO3 NO2 have still been well within acceptable limits, personally for the relatively low expense of water conditioners I wouldn't fill a tank without treatment (some fish can just tolerate chemicals water conditions more than others )