Top Fin (PetSmart Gravel) alters water chemistry?

[MidnightPyro]

This has made me kind of nervous after talking to a few people, so hopefully I can explain what I've learned and people can tell me I'm just paranoid. I picked up some black gravel at PetSmart, but it says it may contain minerals that'll alter pH. Okay, fine enough, but after doing some reading, it seems as though the gravel *may* contain Calcium. According to what a few people told me, if the gravel's paint wears off (and it's Calcium), it'll react with the CO2 in the water forming Calcium Carbonate, which would raise kH.

Now, KH isn't a huge concern, except I have a planted tank, and a high KH would mean it'd be much harder to get CO2 levels correct for plants. I'm not too sure if this is just general paranoia or a real issue here.

I broke open a few pieces of the gravel, and it *looks* like quartz, but when I added it to vinegar, it let off a few bubbles and then stopped, so I'm not too sure whether the stuff is calcium or quartz, or even if it is calcium, whether I'm overexaggerating or not. Can anyone shed some light on this?

The gravel is just 'Top Fin Premium Aquarium Gravel', colored black, that I bought at PetSmart.

Thanks for your help as always everyone!

 

[rrkss]

Raising the kH will not affect CO2 levels in the tank. Some plants like valisneria and anacharis have the ability to extract carbon from Carbonate Hardness so not a problem for the planted tanks. This increase in kH can be corrected by waterchanges anyways.

 

[FreddytheFish]

I've had Top Fin black aquarium gravel for about a year and it has not done anything to the water quality.