how does this snail's shell look?

[lorindaleigh]

I hope I am just being paranoid but since I lost an apple snail and a fish this week I am giving everyone in my tank some serious looking over. I've always notice these lines on my female apple snail. She had them when I bought her, and they have grown with her shell. They don't look like they penetrate through the shell so I haven't worried about it. However, I noticed that the front of her mantle, has a yellowing color to it. I can't remember if that has always been there or not. Does her shell look like something I should be concerned about? She's a very active snail and she seems happy. I give her fresh veggies (not as often as I would like to be able to though), algae wafers, and calcium pills.

Thanks for your help!
Here are the pics Please ignore my algae, I like to keep it on the glass for my picky pleco that I still can't get to eat anything but algae.

 

[Lupin]

The mantle doesn't look good at all. Poor darling still gets it after all your efforts? It doesn't appear to endanger her on the other hand though. What's the temperature?

 

[lorindaleigh]

****! Temp is at 75, shes in the 20 gallon. When I saw it last night I put her a 1 gallon overnight with a calcium pill and spinach leaf. She wouldn't touch either so I put her back in the 20 gallon this morning. She moves around normally. What is it that's cause this problem with both of my snails? That test kit better get here today! Last time I tested my water, my results were

Ammonia-0
nitrite-0
nitrate-20ppm (but this is the lowest that the kit showed)
Ph-7.2
Hardness-Didn't write it down but I remember that it was dark brown on the strip)
I tested with mardel 5 in 1 strips

I do daily water changes so my nitrates shouldn't be too high.

 

[shawnhu]

Probably a lack of calcium, or very soft acidic water. Once you get your kit, and verify the pH and hardness, you can use crushed coral to increase the hardness and pH. You can crush calcium and mix it in as a jello with other foods.

 

[Bubbles2112]

You can also get a cuttlebone (for parakeets) and place it into the tank.

 

[msjinkzd]

I would recommend putting some crushed coral in your filter to buffer the water. The damage that is there is irreversible, but you can help her keep the shell she has left and she will also regrow more from the inside. The new growth can be in better shape though by continuing to feed a calcium rich diet and preventing erosion from your soft water. Ideally you would have your pH up a bit higher (hardness really) around 7.5-8.