Black Devil Snails broken Shell

I have 3 black devil snails in my aquarium I have had them for around 3/4 years now and they’ve always been fine, they still are fine but I’ve noticed that the tip of their shells have started breaking I have looked online everywhere but cannot find out whether this is natural or not and if there is anything I can change to help them or if there is any way to treat it if it needs treatment. Some of them are worse than others, my tank mates have not changed dramatically over the years of keeping them so I do not know what could be causing this.
I forgot to add I was originally sold these snails as rabbit snails but upon reading about them I believe they are black devil snails as I’ve heard a lot of pet shops sell then under the wrong species

 

Other than calcium additives, can't think of anything. Most likely from years of dragging their shells around. Imagine they move pretty similar to rabbit snails?

 

I wonder if he fell off the glass and smucked it on a rock or something.

Do you know how hard your water is?

 

The water in my area is quite hard but we use water treatments so that should be fine I think when I do a water test it all comes back as it should

The water in my area is quite hard but we use water treatments so that should be fine I think when I do a water test it all comes back as it should

My partner thinks it might be growing but I don’t know? They’ve always been the same size, I’m not sure how long they live but I think they were fully grown when we bought them as they were already quite big

 

The water in my area is quite hard but we use water treatments so that should be fine I think when I do a water test it all comes back as it should

I was just asking because harder water is good for snail shells. What are you treating the water with?

 

We have just done a water test kit rather than using a strip and the KH & general hardness are a bit too high

 

What is too high? My GH is 16 and KH is 9. Are they higher? Yes strips are inaccurate sometimes.

 

We have just done a water test kit rather than using a strip and the KH & general hardness are a bit too high

Sorry I have just seen you posted before, we are currently treating for white spot & ich

What is too high? My GH is 16 and KH is 9. Are they higher? Yes strips are inaccurate sometimes.

The Gh is around 14 and KH is 11

 

Well it definitely is not too soft of water. It does look more like a big chip than deterioration to me.

 

Well it definitely is not too soft of water. It does look more like a big chip than deterioration to me.

I thought so too it’s just strange how it’s so bad on one of them it has nearly lost the whole end tip

 

You'll be happy to know that black devel snails have a natural breakdown of the tip
This only happens with adult snails

 

You'll be happy to know that black devel snails have a natural breakdown of the tip
This only happens with adult snails

Ahh thank you I’m so glad I was worried it might die if it had been seriously injured. One of the others has a bit of decay in the top but not as bad as the one in the photo

 

They always get chips out of them especially on top when they fall so I imagine the other one as had his chip from a fall