Nerite Snail Shell Deterioration

[ricthefishman]

Hello, I am new to the forum and am wondering if someone can help me with a problem I am having with my Nerite Snails. My snails have developed "pits" in their shells. From what research I have done I found out that it could be due to a calcium deficiency and/or low pH. Does anyone have any advice on how to fix this? The tank that they are in is a 20 gallon planted aquarium with a variety of tropical fish species including tetras, cory catfish, pencilfish, bolivian rams, and some others including shrimp. I don't use my tap water because it is too hard for my fish, so I purchase deer park spring water to do water changes. All of my fish have been doing well for 2 years now in this water, but the snails appear to need some help. Any information would be greatly appreciated.

 

[Mebbid]

What's the ph of your tank vs tap water? Using spring water might very well be the cause of your problems.

 

[ricthefishman]

Thanks for your reply. The ph of my tank water is around 6.8 and the ph of my tap water is around 7.8.

 

[Fishfur]

I think the likely issue is lack of hardness in the water, that is, lack of calcium in the water column combined with acidic pH. Have you tested your GH ?

Nerites come from tidal flats, where they are regularly exposed to full marine water conditions, which are very hard and alkaline. They do best in hard, alkaline water. If there isn't enough dietary calcium, they're that much more vulnerable to acid erosion.

You might want to try mixing tap water with some RO/DI from the store, but only to the point where it's still at least pH 7 or higher, and add calcium blocks to the tank for the snails to munch. I find the ones they sell with spirulina in them, vacation feeder blocks, work well for me, but my pH is not acidic, so in your water as it is now, they may dissolve too quickly to be helpful.

Fish can adapt to wide ranges of pH and hardness, what they need most is stability. If you choose to change the tank parameters to favour the snails a bit more, make the changes gradual, so as not to shock everybody with sudden change.

You might also try making snail O..a snail diet bound with agar or gelatine. Add plenty of calcium to it, and some spirulina, as Nerites can use algae. They'l eat some veggies but not many have enough calcium in them to help much. Recipes have been posted here and online.. a search should find you several to try.

If you continue to keep them in this water, the deterioration will probably continue to the point the snails die.

Edit.. I realize you have tetras which prefer a slightly acidic pH, but they are kept in a wide range of water conditions, as I said, stability is most important to them. If you can keep the tank pH just at 7 or very slightly over that, and be sure of a GH of 4 or more, the snails should do better and the fish should be just fine. I keep Danios & Beckford's pencilfish as well as a variety of cories, kuhli loaches, CPDs, Chili rasbora, cherry barbs, cherry shrimp, bamboo shrimp, ghost and vampire shrimp, all at a pH of around 7.4 and quite hard, which is the tap water this area has. All happy and healthy.

 

[ricthefishman]

Thanks Fishfur! My pH is around 6.8 and my GH is around 4. Will raising my pH by .2 really make that much of a difference? Since my GH is right where it should be, I don't think that I need to do anything with it. I use spring water. Could this be part of the problem? I like your recommendation of using DI water mixed with my tap water.

 

[Fishfur]

The problem is that acidic water dissolves the calcium layer from the outer shell.

And while you may think there is little difference between 6.8 and 7 in pH.. remember, the pH scale is exponential.. one point difference is ten times higher or lower than the next point above or below. So there's 20 points between 6.8 and 7. Between 6 and 7, its 100 points. So it makes a big difference. Edit..

GH of 4 is minimum, a bit higher would be more appreciated by the snail. It's a general indication of the hard minerals in water.. calcium and magnesium. You can meddle with mixing tap and RO/DI to get a nice middle ground you can replicate with each water change.

Edit.. out of curiosity, have you tested the spring water to see what it's pH and GH are ?

 

[ricthefishman]

Good point. Thanks! I have not tested the pH and GH of the spring water specifically, but I'd assume that it would be similar to my aquarium water. What GH should I shoot for then? Also, how do I know if the GH is more from calcium or from magnesium? Could my water be higher in magnesium and low in calcium?

 

[Fishfur]

The only way to tell if you have more calcium or magnesium is to get a GH and KH test. GH is general hardness..calcium and magnesium. KH is carbonate hardness, or calcium.

So if you have low or no KH, you have little or no calcium in the water. If this is the case there are remineralizing products you can use to raise either GH or KH or both. Salty shrimp is one, there are others. Often used by shrimp keepers to remineralize RO water they use to keep crystal or bee shrimps, which are much more sensitive than cherry shrimp are, but have similar needs for calcium as snails do, since they also have shells of a sort.. their exoskeleton.

I would not assume the spring water is similar to your tap water at all. It could be very, very different depending where it came from.

 

[wildroseofky]

You can add human calcium supplements, antacid tablets, eggshells, or cuttlefish bone to your tank. The snails will eat it and get the calcium they need. Dandelion greens and spinach are high in calcium so you could also feed them that. I have neon tetras, mollies, guppies, two types of shrimp, and three types of snails in my tanks and my Ph is 7.6. The tetras are fine. A PH below 7 is hard on snails. It would be good if you could at least raise it to that. You can patch holes with crazy glue and pieces of eggshell if they get too bad. As long as the pits do not expose their soft bodies they will be fine.