4 different fish found dead, not sure whats killing them ??

[Goose3080]

just completed a 50% water change (100 litres), 4 bottles of this (below), I use a siphon to take the old water out into 1 of these bottles which is only used for waste water x 4 times and tip it down the toilet, then I have another 3 of these bottles full and heated to go in (treated with seachem prime), to make the 4th up I just simply added 3 kettles of boiled water and topped the rest off with cold water, thats a battery powered pump which I use to transfer the new water to the tank, i'll do the same again in a couple of days.

 

[GaryE]

My fishkeeping life is so much easier with low hardness, low pH tap water.

For a frame of reference, right now in one of my QT tanks, I have some tetras and Corys that all came from the same set up at the dealer's place. So I QTed them together. There's something, I'm going to guess a virus, working through the tetras. The Corys seem fine, which suggest it's viral. A bacterial problem would kill everything.
The dish have died, one or two every three days or so over a month now, with absolutely no warning symptoms. I've sat and studied the fish in there looking for clues, and they all look great until they don't. So I keep a hard quarantine on the tank and remove the deads as they appear. I am absolutely powerless.
The water is good, there are still 20 tetras and 6 Corys in a 75 gallon planted, the food is good, the heater is reliable... The tank beside it, with no farm raised fish but identical size, decor, filtration, water and temp is rolling along just fine.
I've only lost one fish this past week, so I hope the outbreak is burning itself out.

I could throw all kinds of meds in there, but it wouldn't matter. I've worked in the fish business and I've seen this pattern before. The fish are suffering from ^%^$ #$#@%&^ ^&^%, or possibly ^%^$ #$#@. With luck, I'll finish up with a smaller group of fish. With poor luck, I will have a Cory tank with no tetras.

What we don't know about fish diseases is way more than we do.

 

[Goose3080]

My fishkeeping life is so much easier with low hardness, low pH tap water.

For a frame of reference, right now in one of my QT tanks, I have some tetras and Corys that all came from the same set up at the dealer's place. So I QTed them together. There's something, I'm going to guess a virus, working through the tetras. The Corys seem fine, which suggest it's viral. A bacterial problem would kill everything.
The dish have died, one or two every three days or so over a month now, with absolutely no warning symptoms. I've sat and studied the fish in there looking for clues, and they all look great until they don't. So I keep a hard quarantine on the tank and remove the deads as they appear. I am absolutely powerless.
The water is good, there are still 20 tetras and 6 Corys in a 75 gallon planted, the food is good, the heater is reliable... The tank beside it, with no farm raised fish but identical size, decor, filtration, water and temp is rolling along just fine.
I've only lost one fish this past week, so I hope the outbreak is burning itself out.

I could throw all kinds of meds in there, but it wouldn't matter. I've worked in the fish business and I've seen this pattern before. The fish are suffering from ^%^$ #$#@%&^ ^&^%, or possibly ^%^$ #$#@. With luck, I'll finish up with a smaller group of fish. With poor luck, I will have a Cory tank with no tetras.

What we don't know about fish diseases is way more than we do.

Thats what im worried about, the 4 that died were fine, no obvious visible signs of illness, one day swimming around, the next day dead, im keeping an eye on the remaining fish, again they all look healthy, all eating, no dead fish today, fingers crossed it stays that way, im kind of hoping it was the cats, the water is crystal clear now ive done the big change, im yet to test the parameters again, i'll probably do it later this evening after its had a chance to cycle through the filter, the filter sponges were all cleaned out on friday evening, unfortunately for now thats all I can do.

 

[Slaphppy7]

Thats what im worried about, the 4 that died were fine, no obvious visible signs of illness, one day swimming around, the next day dead, im keeping an eye on the remaining fish, again they all look healthy, all eating, no dead fish today, fingers crossed it stays that way, im kind of hoping it was the cats, the water is crystal clear now ive done the big change, im yet to test the parameters again, i'll probably do it later this evening after its had a chance to cycle through the filter, the filter sponges were all cleaned out on friday evening, unfortunately for now thats all I can do.

Always wait a full 24 hours after a WC to test.

 

[Ichthys]

Always wait a full 24 hours after a WC to test.

It’ll be fully mixed within a few minutes.

 

[Slaphppy7]

It’ll be fully mixed within a few minutes.

But, waiting 24H gives what BB (and plants) there are in the tank time to process ammonia (or ammonium)...and the liquid test kits may erroneously register (harmful) ammonia, when in fact it is (harmless) ammonium....the API test kit, for instance, doesn't differentiate between the two

Really has nothing to do with "mixing" ...

 

[Goose3080]

But, waiting 24H gives what BB (and plants) there are in the tank time to process ammonia (or ammonium)...and the liquid test kits may erroneously register (harmful) ammonia, when in fact it is (harmless) ammonium....the API test kit, for instance, doesn't differentiate between the two

Really has nothing to do with "mixing" ...

Im actually living proof of this........I tested all 6 water parameters last night using the API kit and NT Labs kit, PH, GH, KH, NH, NO2 & NO3.

Everything was fine except ammonia which was at 0.2 on both kits, I know this is not dangerously high but id rather it be on zero, and it did cross my mind how it could be so high after doing such a large water change, but I thought id just test again in the morning.

I tested ammonia again this morning (24 hours after doing the water change) and they both registered zero.

 

[Slaphppy7]

Im actually living proof of this........I tested all 6 water parameters last night using the API kit and NT Labs kit, PH, GH, KH, NH, NO2 & NO3.

Everything was fine except ammonia which was at 0.2 on both kits, I know this is not dangerously high but id rather it be on zero, and it did cross my mind how it could be so high after doing such a large water change, but I thought id just test again in the morning.

I tested ammonia again this morning (24 hours after doing the water change) and they both registered zero.

Many aquarists (beginners, usually) will test their water immediately after a WC, believing that their water conditioner should completely "remove" all traces of ammonia...which doesn't happen...GOOD quality water conditioners render the harmful ammonia into harmless ammonium...but the test kits will register ammonium as ammonia

How are your remaining fish doing?

 

[Ichthys]

Sorry, I didn’t read the whole thread properly. I wasn’t thinking about dechlorination, just pH, hardness, etc.

 

[Goose3080]

Many aquarists (beginners, usually) will test their water immediately after a WC, believing that their water conditioner should completely "remove" all traces of ammonia...which doesn't happen...GOOD quality water conditioners render the harmful ammonia into harmless ammonium...but the test kits will register ammonium as ammonia

How are your remaining fish doing?

So far so good, no further losses, no signs of illness, no erratic behaviour........fingers crossed it stays that way, in all honesty they seem very happy and quite playful, colours on the clown loaches and neon tetra's are very vibrant at the moment which is always a good sign as ive noticed when I get a problem with my water their colours start to fade, its a good tell tale sign for me.

My next battle is to get these damn diatoms under control, my water contains silicates, so doing water changes seems to be helping the diatoms, I was thinking of getting some snails, but unfortunately I have clown loaches who love to snack on snails.

 

[Slaphppy7]

So far so good, no further losses, no signs of illness, no erratic behaviour........fingers crossed it stays that way, in all honesty they seem very happy and quite playful, colours on the clown loaches and neon tetra's are very vibrant at the moment which is always a good sign as ive noticed when I get a problem with my water their colours start to fade, its a good tell tale sign for me.

My next battle is to get these damn diatoms under control, my water contains silicates, so doing water changes seems to be helping the diatoms, I was thinking of getting some snails, but unfortunately I have clown loaches who love to snack on snails.

Good to hear the fish are doing well.

The diatom ("brown algae") issue may be a tough one...snails won't help with this, and if your SOURCE water contains silicates (which "feed" diatoms), water changes won't help much, either

BUT, if the substrate is new (or "new-ish"), and produces silicates, they will eventually wane over time, with regular weekly WCs