well it all depends. Snails shells depends on calcium so, you will have to see the calcium hardness of your water. Also only if your water's ph is below 7, will the acidity eat away at your snail's shell.
If IAL is capable of bringing down your GH and KH, but tour water is very hard anyway, it may not have much of an impact at all. this includes PH. if the water is fairly hard, the impact of IAL on PH will be low. as opposed to soft water, where PH change may be dramatic.
That said, I've yet to lose a fish or planta to IAL. so dont worry about it and use to your hearts content. I do prefer clear water, so I clear it out once I'm done. you dont have to. instead you can find a middle ground between tea colored water and light penetration :)