So,I have a bunch of guppies. They all keep dying,I presume from ick as that is what they are showing symptoms of. However I have done everything possible to get rid of this ick,I have tried ick medications along with a multicure and a bunch of parasite stuff too,I've done all of this consistently,even moving fish into another tank and doing them in batches and quarantining them. Nothing seems to work. I've also had fish who are skinny and die(which is why I used the parasite stuff), some that look healthy and then straight up die,others who are only a few months old start dying too. Some of them look like they are gasping for air but all the levels in the tank are fine and I do water changes regularly,their gills are looking fine. Now I've even got one fish who was completely fine yesterday and now she looks like she is bleeding internally,like I can see the bones in her spine are completely red,she is also red around her belly where her gravid spot would be and her head also. I have literally tried everything under the sun to stop these guys from dying,they are in a 90 litre tank and I've got some smaller ones in using for quarantining. As far as I know there is no bullying going on in the tank. I have no idea what to do,like I've never seen anything like this within my three years of breeding guppies.

I am so sorry for this.

Maybe there is any illness due to your water / water quality or any deco you use in the tank? Kind of a continuous intoxication?

On the other hand, as much as I know, a lot of guppies are very very inbred and have health problems - at least I was told this in a fish tank forum from guppy breeders when I had problems with them several years ago.

The water quality is fine,and I've used the same decorations over the years I've had the tank. I have a filter on the tap water as well so chlorine gets in when I do a water change,I also use stress coat every time I do a water change so I don't think it's water quality. Yeah,I am aware of the inbreeding problems,I always make sure to get new stock in whenever I can. I have had health problems in my guppies consistently in the past but nothing to this scale,like I've had then get sick,given then medication and everything is fine but now I've had this problem for months and no matter what I do it doesn't go away.

I'm sorry to hear this is happening! I know how stressful it can be having sick fish.

Have you double checked to make sure your level testing is correct? I've personally had testing kits go bad.

How many guppies do you have in your tank? It could be you are over-stocked and possibly they are nipping each other or having issues from overcrowding?

Are your numbers of male and female in a good ratio?

This is a great calculator to use to make sure the dimensions of your tank, pump capacity, and fish number are all compatible.

I personally never go more than 75% capacity, just to play it safe.

If your decorations are not straight rock, driftwood, or live plants I would remove ASAP. I have heard of decor starting to leach out chemicals after years of being in a tank.

Do you have any live plants?

Do you have a bubbler or air stone? Additional oxygen being pumped into a tank can always help health.

I do have a higher ratio of males than females at the moment because of them being sick I can't sell them,unless I find someone who would willingly take in sick fish. I was planning on giving them to someone else but I haven't heard from them if they still want the guppies. I don't have any live plants in the tank at the moment because when I did have them they got eaten by snails. Most If not all of the decorations I have in the tank I got a year or two ago. I haven't seen any bullying in the tank yet but it is always a possibility. I don't have any extra filters in the tank I only have the one it was built with.

Sounds like chlorine poisoning. It can cause fish to 'gasp' and have red spots appear. I'd recommend adding additives to the water designed to remove chlorine and get some bubbler stones to help aerate the water.

They don't have red spots. I already have a filter on the tap water and always add stress coat after a water change which helps calm the fish down and get rid of chemicals that are harmful to the fish.

I agree with everyone else on chlorine poisoning. I'd recommend an airstone/bubbler aswell.