Lace rock effect on pH

[enricosonic]

After picking up a nice looking chunk of lace rock about the size of a car battery, I since have read it may raise pH. This is a new, uncycled 75g tank with a few small live plants and some fairly large pieces of driftwood that are still floating at this point.

My pH is naturally around 6.8 to 7.0. Will the driftwood counter the lace rock and/or is there any cause for concern whatsoever?

 

[Colin_T]

pictures of the rock?

have you poured some vinegar on the rock to see if it fizzes and reacts?

 

[enricosonic]

No, I only rinsed it thoroughly with water and scrubbed it with a stiff-bristled brush then placed it. It's been in there maybe 2 hours, any point in the vinegar thing now?

A couple pics:

 

[enricosonic]

I’m not even certain it’s lace rock really.

 

[Byron]

You are in Seattle (Washington state I assume) so you have very soft water (as we do up in SW BC). The GH and KH are very low, probably basically zero. See if you can track down these numbers for your source water. The GH and KH affect the fluctuation of pH. Organic matter like wood, dried leaves, and obviously fish excrement will work to lower the pH, and with very low GH/KH it will; reverse is also true, that calcareous substances will raise the pH because of the very limited buffering capacity. I've no idea on the composition of lace rock, if that is what this is; it does have a limestone/basalt look to it, but that's just a guess.

 

[enricosonic]

Yes you’re absolutely right, the GH and KH here are near zero. A lot more plant life will soon be coming as well as the aforementioned driftwood. I don’t know how it works chemistry-wise but there’ll be much more surface area that is wood than whatever this rock is. But then the rock is super porous.

 

[Colin_T]

The rock looks like sandstone, which will be calcium based and raise the pH. You can test the rock by taking it out, letting it dry, than pour some white vinegar on it. If it bubbles and fizzes, it is calcium based and will raise the pH to some degree. This might be useful if you plan on keeping fishes that come from water with a pH above 7.0.

 

[enricosonic]

OK. This should work out just fine then. I do plan on keeping a couple of angels, yoyo loaches, a pleco and maybe others in that pH range. As long as it’s not going to bump me up to 8.0 or more all’s well. Thanks Colin.

 

[Byron]

OK. This should work out just fine then. I do plan on keeping a couple of angels, yoyo loaches, a pleco and maybe others in that pH range. As long as it’s not going to bump me up to 8.0 or more all’s well. Thanks Colin.

All of these fishes will be fine with an acidic pH below, even well below, 7.