Bronze corydoras

Hello,
I have bought, only yesterday, 3 more bronze corydoras in the pet store to add to my 64L tropical tank and I have noticed one of them scratching on the sand. Is it something I should worry about? My water was tested yesterday and all the parameters were good. The tank is currently heated at 25 degrees Celsius. I would really appreciate your advice. Thank you!
Céline

If its constantly scratching itself against the sand (flashing) then could be a sign of ich or gill/skin flukes (parasites). Does the fish have tiny speckled white dots? (Search Google images for ich fish)

How did you acclimate the cories? What is your GH?

What are the numbers of your parameters?

So I had typed out a whole reply because I didn't notice the cory on his side in the pic until after I zoomed in when viewing a 2nd time. Deleted the reply.

I would QT it if you can until you get more advisement.

Looks very healthy to me. Could be something in the water causing some irritation. Have you recently done a water change? Do you use a water conditioner to remove chlorine/chloramine? Do you use any cleaning products around the tank ie furniture polish, window cleaner? Or have any candles? Need to be careful to keep these things well away from the aquarium. Keep an eye on her (i think? @NCaquatics ) and if she carries on flashing, do a big water change using a water conditioner such as Seachem Prime. Also looks like she could do with a good feed. Do you have some dedicated bottom feeder food?

Thank you so very much for this how do you see she would do with more feeding? Is it from her belly shape? I usually feed my corys once in the morning (I feed them vitalis xs as they struggle with the larger pellets). As for the water, I use bioactive tap safe plus with aloe vera every time I do a water change. I also use easy carbo (1ml every second day), profito fertilizer (5ml a week) and Tropica premium nutrition every week (3 to 4ml) for my plants. I have only been using the plants fertilizerNot sure if any of that can disturb the fish?
I usually do a water change once a week and tomorrow should be the day I do a water change so I think I will do it tonight.
Thank you for all your advice!

And I forgot this one. As for cleaning the tank, I have completely emptied it 2 weeks ago, I only used tap water and a clean sponge to clean it. I have put new plant substrate and washed sand over it. I saved most of the water from my tank prior doing that so I had only to complete with about 8-10 litres water Treated with the tap safe.

Its plausible your parameters may be different from the stores water and thats caused some agitation while it adapts.

Thank you

One thing jumps put at me - the EasyCarbo. Most of these liquid carbon products contain glutaraldehyde which is a powerful disinfectant which is used for sterilising surgical equipment and in embalming fluid. It can kill some plants in even just a small overdose, so it is not going to be good for fish. I won't use these products in my tank!
Easy-Life's website doesn't say what EasyCarbo contains, the bottle may have a list of ingredients.

Thank you for your message. I was not aware of this. I have only recently used fertilizers in my tanks as I wanted to give my plants a boost. I have checked the bottle of easy carbo and it does not give anymore details. I am attaching a picture.
Would you know any alternative to feed the plants?
My aquariums have been running for about 5 years, my first cories are about 4 years old but I was never successful with plants (I did not use fertilizers then, only the tetra substrate which I changed every 2 years on average). This time around, I would really like to be successful with the plants too.
As you may have read from my previous posts, I have only recently changed the substrate and top layer in my tank.
My tank has a relatively low need in CO2 injections (this is why I originally decided to add it only every second day instead of everyday as stated on the bottle) so I may be able to stop it completely. Thank you!

I am not a plant expert by any means - I have all slow growing plants which don't need CO2 in any form, and floating plants which get CO2 from the air. I know there are some plants which need a lot of light, fertiliser and CO2 to grow well, but most plants get enough CO2 from fish respiration, and waste decomposing in the substrate. As you have recently changed the substrate, you won't yet have the micro-organisms to break down waste but they will grow.

I don't recognise the plants in your tank so I have no idea if they need added CO2 or not

Thank you for your advice. I will try without the fertilizers for now and see how it goes over the next couple of months