# What's the deal with seashells?



## puppyrjjkm (Aug 2, 2009)

I've heard conflicting stories, some that seashells are harmless, others than seashells raise pH to levels that will kill fish. So what's the truth on these? I have tons of seashells mostly ones bought for decoration (yet are "real" seashells) that I would love to use. Are these okay in fish tanks?


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## BlueHaven (Jul 17, 2010)

Test it out first. Put one in a separate tank/ fishless bowl with condioned water all the same as your betta's home and test it with API or a good test kit. See how much it raises the ph. If it does not go higher than what is recommended for bettas, then you can use it. I am not sure if it will raise the ph automatically or after some time.
But you might still want to keep an eye on it if you do end up using the seashells...


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## CrankyFish84 (Nov 5, 2010)

Ok this might sound stupid but...aren't seashells mostly the same material as snail shells? 
Do empty snail shells rot and/or change the water?


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## SemioticSleep (Mar 31, 2010)

Sea shells and snail shells both are made of calcium. I tested out my sea shells in a bamboo plant i had since bamboo plants are intolerable to salt and other harsh things like pH. My plants seem to be doing fine so I might just put a FEW shells in my tank. But sea shells really shouldnt hurt your tank since they are in Cultured gravel which is a fav among betta keepers. But don't put to many or leave them facing up your betta could get stuck in one of them.


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## Jupiter (Aug 30, 2009)

Well, calcium is known to bring up PH, which is what shells contain...so yeah, test it out first just to be on the safe side.


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## Kribby (Nov 21, 2010)

There are a few things to concider about adding seashells to an aquarium. Firstly they are a calcium carbonate base which means that in unbuffered water they will raise the pH to 7.6 (max). As someone that keeps and breeds african cichlids this is not something I concider to be high. I keep those tanks around 7.8 to 8.0.

While that is all said and good, most tap water does have natural buffering capacity that changes with location. This can be measured with a GH test kit. What this will tell you is how hard you water is and how likely it will be able to buffer changes in what is added into the tank. If the water is soft, then the seashells will have a greater impact than if the water is hard. This is because as the shell breaks down, which is will do, it will overcome the buffering capacity of your tank water if it is soft.

All in all, the most important thing for fish is consitancy. Most fish have an amazing ability to adapt to the water conditions of their locality. Which is why we are able to ship them all over the world without worrying about the water chemistry at their destinations. So even if adding the shell raises the pH a little bit, it shouldn't be enough to bother the fish, as long as it is able to be kept in those conditions long term.

So check your pH, the hardness of your water, and see how much of an affect one or two shells has long term.


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