Why are my fish dying

[LTurner97]

I’ve had my fish tank for about 2 months now and the last week I’ve had fish die for no reason , a month in I had a few ill ones and unfortunately they passed , but this week I’ve had a Cory and a Otto pass , I’ve added my water parameters which I think read good , any advice on what the issue may be

 

[Helina]

Hey!

Sorry to hear that! I had a quick look at some of your earlier posts: is it so that you have now changed to new filter as well as new bottom substrate in under a week? That could be risky to do. I'm not an expert though in how fast a possible nitrite spike disappears so I can't say what's the cause. With Otos I'm also thinking if they get enough algae on surfaces yet to feed on, or are they successfully been eating added foods?

 

[LTurner97]

Hey!

Sorry to hear that! I had a quick look at some of your earlier posts: is it so that you have now changed to new filter as well as new bottom substrate in under a week? That could be risky to do. I'm not an expert though in how fast a possible nitrite spike disappears so I can't say what's the cause. With Otos I'm also thinking if they get enough algae on surfaces yet to feed on, or are they successfully been eating added foods?

I haven’t changed the substrate was thinking closer to Xmas due to changing the filter probably 2 weeks ago , they eat the extra food I add into the talk and all look plump when I see them on the glass so idk

 

[Colin_T]

pictures of the fish (dead and alive if you have them)?

have you added anything to the tank in the 2 weeks before this started?

 

[LTurner97]

pictures of the fish (dead and alive if you have them)?

have you added anything to the tank in the 2 weeks before this started?

The first photo with the betta in shows a few of the fish I have , the second with the panda Cory was a day before he passed , all I can think is he looked a little skinny , the last is the picture I received from my mum today while at work of my Otto who has also passed

 

[Colin_T]

What fish have died so far since you set the tank up (besides the Corydoras and Otocinclus that died the other day)?

Have you added anything to the tank in the 2 weeks before these latest fish died?

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The water tests appear fine, so that's good.

One of the neons in the first picture has some white on its back above the blue line. That could be excess mucous from something in the water irritating the fish or the start of a disease (Columnaris, Costia or just excess mucous?). More pictures of the neons might offer more info.

A lot of the neons in the second picture have excess mucous (white bits) on their fins. This would suggest there is something in the water irritating them.
The Cordyoras looks fine in that picture.

I can't tell anything about the Otocinclus in the third picture.

The male Betta has damage to its tail, which could be from bites or getting caught on things in the tank (possibly the driftwood or rock).

None show any real signs of disease so I would do big (75%) daily (or every second day) water change and gravel clean the substrate for a week or two and monitor them. If anymore look off colour or die post pictures of them immediately.
Make sure any new water is free of chlorine/ chloramine before it's added to the aquarium.

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Do you have separate buckets and hoses specifically for the fish tank?
If not, get a couple of new buckets and use a permanent marker to write "FISH ONLY" on them. Use those buckets for the fish and nothing else. Make sure the buckets are made from food grade/ food safe plastic.

Make sure you don't have anything on your hands or arms when working in the tank. This can be perfume, hand sanitiser residue, soap residue, grease, oil, cream or anything else that might come in contact with the water.

Make sure nobody is spraying, painting, smoking or using anything that creates fumes in the room with the aquarium.