Water Hardness Questions

[ellamay]

I've attached a photo of the kind of rock I have in my tank, would this affect the water hardness in any way? only other things I have in my tank is plants and a cave and some smooth pebbles.
My water hardness is normally around 20. I've been trying to find a type of cory which will be suitable for my tank parameters but a lot of them prefer softer water.

I'm pretty sure taking these rocks out wont make any difference but they were pretty dusty when I got them (i did wash them) and I wasn't sure if tiny bits of the rock might be dissolving ?

 

[WhistlingBadger]

Hi, Ellamay. Can you tell us a little more about where the rock came from and what kind it is? You could try the vinegar test. Put a drop of vinegar on the rock. If it fizzes, it's probably limestone or something closely related, which will raise your pH and hardness over time.

 

[Slaphppy7]

I've attached a photo of the kind of rock I have in my tank, would this affect the water hardness in any way? only other things I have in my tank is plants and a cave and some smooth pebbles.
My water hardness is normally around 20. I've been trying to find a type of cory which will be suitable for my tank parameters but a lot of them prefer softer water.

I'm pretty sure taking these rocks out wont make any difference but they were pretty dusty when I got them (i did wash them) and I wasn't sure if tiny bits of the rock might be dissolving ?

Dry them, and put some white vinegar on them...if it bubbles, not safe...if not, safe

 

[Slaphppy7]

Hi, Ellamay. Can you tell us a little more about where the rock came from and what kind it is? You could try the vinegar test. Put a drop of vinegar on the rock. If it fizzes, it's probably limestone or something closely related, which will raise your pH and hardness over time.

Great minds....

 

[Colin_T]

My water hardness is normally around 20

20 what, ppm or dGH?

The white rocks look like limestone, which will raise the pH. It can help increase the GH too but it won't be a lot.

As others have mentioned, put some vinegar on the rock and see if it fizzes and bubbles. If it does, then the vinegar (which is an acid) is reacting with the calcium in the limestone.

Limestone rock is fine if you keep fish that come from water with a pH above 7.0. However, if you keep fish that come from soft acid water (pH below 7.0) then find smooth river rocks or something else that doesn't raise the pH.

 

[ellamay]

Hi, Ellamay. Can you tell us a little more about where the rock came from and what kind it is? You could try the vinegar test. Put a drop of vinegar on the rock. If it fizzes, it's probably limestone or something closely related, which will raise your pH and hardness over time.

It was called ocean rock and it’s from Maidenhead aquatics (in the uk). If I do this test will I be able to use them after that or will I have to throw out the one I put vinegar on? I’ll get some vinegar tomorrow.

 

[ellamay]

20 what, ppm or dGH?

The white rocks look like limestone, which will raise the pH. It can help increase the GH too but it won't be a lot.

As others have mentioned, put some vinegar on the rock and see if it fizzes and bubbles. If it does, then the vinegar (which is an acid) is reacting with the calcium in the limestone.

Limestone rock is fine if you keep fish that come from water with a pH above 7.0. However, if you keep fish that come from soft acid water (pH below 7.0) then find smooth river rocks or something else that doesn't raise the pH.

I’ve just checked and I’d converted it from ppm to dGH wrong. It’s consistently about 150ppm. Which I think is around 9dGH? So it’s not very hard water then is it.

 

[Back in the fold]

150 PPM is not very hard at all. But, as @Colin_T noted, that looks like limestone to me too and in time it will slowly add mineral content that will buffer you more to an alkaline pH and make the water a bit harder.

 

[ellamay]

I've been using two different water test kits, one with ppm and one just the dgh so I think I got a bit mixed up. Thank you for the help! @Back in the fold

 

[WhistlingBadger]

It was called ocean rock and it’s from Maidenhead aquatics (in the uk). If I do this test will I be able to use them after that or will I have to throw out the one I put vinegar on? I’ll get some vinegar tomorrow.

No, just rinse it off and it's fine. It only takes a few drops.

 

[Colin_T]

It was called ocean rock and it’s from Maidenhead aquatics (in the uk). If I do this test will I be able to use them after that or will I have to throw out the one I put vinegar on? I’ll get some vinegar tomorrow.

It will be limestone.

Splash some vinegar on it and watch it fizzle. Then rinse it off under tap water.

 

[ellamay]

It will be limestone.

Splash some vinegar on it and watch it fizzle. Then rinse it off under tap water.

If it’s limestone would you recommend taking it out and getting a different kind of rock?

 

[Colin_T]

If it’s limestone would you recommend taking it out and getting a different kind of rock?

It depends on what fish you are keeping in the tank.

If you keep livebearers like guppies, platies, swordtails and mollies, leave it in. If you keep tetras, barbs, corydoras, angelfish, take it out.