Will most rocks have no effect upon pH?

[WhistlingBadger]

I recommend having a friend who is a geologist. That's how I work these things out.

 

[Naughts]

Ph, & it's components if leached into the water would likely push it down, rather than up, as would limestone

How does an alkaline rock such as limestone acidify the water?

I've been putting vinegar on rocks collected from creek to see if they start fizzing to check if they are alkaline... I've never actually seen one that does though, so now I'm doubting that this actually works

Vinegar is not strong enough to produce a reaction. Geologists use hydrochloric acid, but it's a dangerous substance.

 

[Magnum Man]

Sorry I wasn’t implying lime stone would lower the Ph…

I reread the post, I don’t see where I said anything like that???

 

[GaryE]

pH is unimportant here. Your concern should be hardness, which does matter a lot. That's why I would measure tds, conductivity, or GH, DH, depending on what you have to test with. The rocks I pick up around here have no effect on tds or conductivity, which goes with what I see in the field guide.

 

[Ellie11]

Thanks for all your help. I pulled the slate & couldn’t find basalt except in large expensive quantities online or tiny pellets which is not the look I’m going for. I can’t take any chances on settling up this altum tank.

 

[PygmyPepperJulli]

So, (sorry for being such a thread invader ) just going off what others have said and Ellie has concluded, and wanted to make sure these things are right-

1. Vinegar is not an effective tester for alkaline/hardness increasing rocks (because it a. Isn’t strong enough and b. Only helps with pH rather than hardness)
2. Most rocks actually don’t increase/change the pH or hardness of water (and if you want your water not to change, don’t add limestone etc.)
3. Best way to check if it WILL alter your water is check the hardness of water in seperate container compared to normal water, (which I can’t do, unfortunately) or identify what the rock is and do some research (which, as a wanna-be rock nerd, I am fine with doing ).

Only asking because I have put soooo many rocks in my soft/acidic water tank just doing the fizz test and then started panicking when reading this thread.

And good luck with your tank Ellie, angels are on my wish list! Bet it’ll look great!

 

[GaryE]

I think Ellie's tank is one we'd all like to see. Road trip!

This is why everyone is vague about where they live....

I follow what @PygmyPepperJulli is suggesting. I have hydrochloric acid if I want to see fizzes, but I don't want burns on my skin, so I use a field guide. I actually find rock hunting interesting and fun. They are heavy, and never right where you live or where you park your car. I have a friend who's a geologist but 1000 km away from here. She keeps saying she wants to visit, and when she does, I'll get a course in local rocks. Til then, I pick up likely looking rocks while walking the dog, and make the occasional side trip to spots that look good if I see them. I almost have enough rocks now.

For some strange reason, when I moved 1000km to come here, I didn't bring the 20 years worth of interesting rocks I'd collected to decorate my tanks. They became an improvised rock garden on the side of the old house. That pile of rocks from many places can confuse an archaeologist in 999 years.

 

[Essjay]

1. Vinegar is not an effective tester for alkaline/hardness increasing rocks (because it a. Isn’t strong enough and b. Only helps with pH rather than hardness)

Vinegar tests for rocks made of carbonate. These rocks increase hardness (GH) and KH and pH in a tank. (Carbonates and acids in the presence of water react to form carbon dioxide. There's plenty of water in vinegar and the carbon dioxide makes the bubbles)


If you don't mind sacrificing it, API nitrate test bottle #1 contains hydrochloric acid, though it'll be pretty dilute.