Rock that increases pH

[bttay]

I placed some rocks in my tank and later realized that they are not inert. I did a little experiment by submerging one of the rocks in vinegar solution that meassured 4.3pH and the pH went up to 6.5 the next day.

No wonder that my plants developed large leaves. It could be due to the fact that some calcium carbonate from the rocks has dissolved. :P

My question is: Apart from getting "automatic" calcium dosage and inaccurate CO2 messurement, are there other side effects of it? (It would be too late to remove the rock as they are well incorporated in my tank design and some of them are buried deep in gravel).

Thanks.

[victri]

There's probably some lime in the rock. Do they give out bubbles when you soak in vinegar? Apart from increasing carbonates and affecting PH and hardness, they shouldn't affect livestock. You might want to watch your water parameters though.

[bttay]

[quote:414182d397="victri"]There's probably some lime in the rock. Do they give out bubbles when you soak in vinegar? Apart from increasing carbonates and affecting PH and hardness, they shouldn't affect livestock. You might want to watch your water parameters though.[/quote:414182d397]

Thanks for your reply.

I can't see bubbles even when I drop a few drops of vinegar on it. But can hear soft hissing sound when I listen very closely suggesting that chemical reaction is going on.

My water pararmeters so far are not out of control:
pH - 6.7 (tried to lower by increasing CO2 but the drop was minimal)
KH - 4 ( I think is a bit higher than my last tank without the rock which was 2-3)

[Sleepy_lancs]

No no no.. KH should be at least 3. 4 would be better.. anything below that will have PH swing when you turn on or off your co2 injector

[bttay]

[quote:bdfc8c6fa6="Sleepy_lancs"]No no no.. KH should be at least 3. 4 would be better.. anything below that will have PH swing when you turn on or off your co2 injector[/quote:bdfc8c6fa6]

Thanks Sleepy_lancs.
Ya, KH of 4 is good. My tap water KH is only 2-3 and I did not add baking soda to up the KH. I think the rock has done some good by providing carbonate to the water.

[budak]

If your plants are doing ok, keep your rocks since they act as a natural carbonate buffer.....

Juggler, if I recall correctly, had a whole substrate of coral chips/shells in his tank and his plants did wonderfully.

[bttay]

Ya, it seems to be a blessing in disguise which I earlier thought to be a disaster

[Sleepy_lancs]

Just ensure you do regular water change and monitor your KH. It shouldnt be going up and down drastically. If its within proper range, it will be a good solution for you.

[juggler]

[quote:adc3fd3125="budak"]If your plants are doing ok, keep your rocks since they act as a natural carbonate buffer.....

Juggler, if I recall correctly, had a whole substrate of coral chips/shells in his tank and his plants did wonderfully.[/quote:adc3fd3125]

Yep, my first ever planted tank has coral chips forming majority of the substrate. kH can go up to 11 dkH. But water is alkaline most of the time > 7 with only DIY CO2 at that time. Plants are doing OK.

No wonder at that time, when I dose 20ppm K and 5ppm Mg weekly, there's no problem as well because of the big buffer of Ca.

Just monitor to see if you are able to keep the pH within 7 with injected CO2. If possible, then it should be great.