Treating Sea Shells To Be Put In Freshwater Tank

[PeachesNCream]

Hello, not sure where this goes so if it's in the wrong section sorry!!
I want to put the sea shells I have found into some of my freshwater tanks for decoration. How do I treat/coat them so they are safe for my tank??
 

 

[barbeds]

I dont know the answer for sure, but i would think the only problem would be the salt content, therefore is it not just a case of rinsing them off in fresh water for a period of time

 

[techen]

Salt can stick on those for a very long time. I wouldn't recommend using them at all.

 

[fluttermoth]

Shells are perfectly safe, if they've been soaked and the water changed daily for a week or so.
 
They will dissolve, slowly, in freshwater though, which ruins the shells and raises the pH and hardness of your water; not by a huge amount, unless you have hundreds, but you wouldn't want to use them in a soft water tank.

 

[Chad]

I won't go so far as to say "perfectly safe" as they can harbor bacteria, parasites and mess with water chemistry.
Fortunately freshwater can kill almost all of them, but just to be on the safe side I do recommend an iodine dip or as flutter says a long soak. I don't personally feel there is any need to coat them but there are safe clear varnishes made for aquarium décor you could use and that would keep the pH issue in check as well as any residual salt that might linger deep inside the shell.

 

[missdarwin]

Sea shells contain a lot of different types of marine bacteria, as well as frequently holding the sinews and other minute bits of whatever might have been a previous inhabitant. The salt water maintains that bacteria at a low level due to most bacteria not wanting to do anything much in high salinity. Putting the shells into freshwater, especially tropical, may increase the rate of these not so nice bacteria and infect your tank.

As well as that, if your tank is anything less than pH 7, the calcium compounds which can make up the shell will slowly react with the acid in your water and release products into the water (granted, this will be slow and if you're using small amounts of shells you'll probably not notice any difference for a long time)

I'd soak them in freshwater every day, changing the water, and see if you can bung them in a steam steriliser to make sure the Bactria are dead. (Find someone with a new baby, they'll have a steam steriliser) x x

 

[DrRob]

I'm not sure you'll manage to seal most things that go into an aquarium properly, however hard you try (unless you encase them in a lump of resin). The comments on water chemistry and harboured bugs would be my main concerns. Fine for hard water tanks, not so for soft water.

 

[fluttermoth]

I won't go so far as to say "perfectly safe" as they can harbor bacteria, parasites and mess with water chemistry.
Fortunately freshwater can kill almost all of them, but just to be on the safe side I do recommend an iodine dip or as flutter says a long soak. I don't personally feel there is any need to coat them but there are safe clear varnishes made for aquarium décor you could use and that would keep the pH issue in check as well as any residual salt that might linger deep inside the shell.

I'm afraid I did assume we talking about long dead shells, Chad; I should have clarified that! Anything that might be more recently dead should probably be soaked in boiling water a few times and then allowed to dry out completely
 
I actually did mention varnish in my post orginally, but I deleted it! I've never found it working. Varnishing was all the rage for a while 15/20 years ago when more natural looking set ups were coming along, but everyone was paranoid about putting real wood etc in their tanks (gosh, that sounds so silly now! But we were!). You always seemed to get pinholes somewhere that let the water get behind the varnish that made it go 'milky' and flaky. It looked blimming awful!
 
I use shells in one of my tanks to help stop the pH dropping, as I have very soft water and the fish in that tank (emerald dwarf rasboras) prefer it a bit harder.