My corydoras keep dying

Sorry it will not let me upload videos for some strange reason

Kaylab2021 said:

Sorry it will not let me upload videos for some strange reason

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Ah, the video upload function on the site is broken, but if you upload the vids to youtube, can link them here!

The cories do look very pale and skinny to me... not the deep colours and chunky bodies I like to see in bronzes. Tagging @Colin_T for advice, he's our health and disease guy, but I'm certainly alarmed by the photos.

They do all eat i will get more pictures of them just dont know what could be wrong to fix it

OK so what jumps out at me is the substrate

Cories love to snuzzle in the sand, they sift sand when feeding, they love to play in sand where they can dig up food that other fish have missed

Your aquarium is missing sand

Even micro-gravel is better than the standard gravel that you appear to have. They cannot snuzzle what are - to them - rocks when finding their food. Even smooth gravel like yours can hurt them and stress them out...which in turn, along with the inability to snuzzle for food, causes stress, barbel injury and eventual malnutrition and death

You don't have to change out all the substrate....to make a beach of about 25% of the space, just get an old plastic 2 litre bottle (if old fizzy bottle make sure it is thoroughly cleaned out), cut the bottom off the bottle, turn upside down and use the neck of the bottle to first move the substrate away to leave a clear part of the glass bottom, then slowly and very very gently pour sand down through the bottle, slowly moving it about 1 inch above the glass bottom to fill your beach space with sand.

You will find that the Cories will instinctively go to that sandy beach area to feed and to cluster when resting.

Hi there i have actually changed it to sand about a week ago now black sand and i only have a few gravel stones in middle to make a hill but it is all mostly sand now. Also all there barbels seem to be ok none missing or injured. My one bronze and 3 albinos were fine untill i added the new ones into the tank and its the new ones who seem to be acting different. I have added pictures of my new substrate. I also added pictures yesturday of my tests i had done do you think the readings are ok? I couldnt work out how to read the kh and gh? I added 5 drops to kh to turn yellow and 12 to gh to turn dark blue is that reading ok for the kh and gh? Thank you

My lights dont come on untill half 11 so will try to get more pictures of the corys

Theres some new pictures from today they dont seem to be twitching today and all seem to be swimming nicely

I have done another reading today which everything looks ok. Again i can not work out the kh and gh was never any good at maths but i took 5 drops to turn kh yellow and 10 drops to turn gh blue does that read about right for my fish?