Shells In tank with Freshwater Rays?

[rayray]

Here is a picture of them.

 

[wetsock]

nice shell, and yes i think it will increase your PH

 

[IKeepPacu]

What's the vinegar trick. I haven't heard of that?

put a few drops of vinegar on the shells in question, and if it foams up and reacts, its generally not tank safe.

its how ive always checked rocks, read it awhile back several places on the net

 

[rayray]

Thanks Everyone. I don't think I will be using the shells.

 

[epicentyr]

I would say that there is ~0 chance that those 5 shells will have any effect on your PH. When people on the web say that shells will change PH it is usually in reference to shell/crushed coral as a substrate which has 1,000x the surface area that you are questioning. There is no way that that amount of shell will have any impact on your 190 gallon tank.

On the other hand. Are you trying to make stingray-ka-bobs. Those shells look dangerous. They add like 10 different spikes to impale your hand, on top of the poisonous one on your rays.