# limestone?



## Darla4022

is this limestone? I can scratch it on the cement and makes a chalk-like mark.







tia. I hope this post came out ok. first time. Darla4500


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## ken31cay

Drop some undiluted lemon juice on it, if it fizzes then it is most likely limestone.


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## Darla4022

I put vinegar on it and it does fizz some, I want to decorate my new peacock tank with them. is there a limit on how many i can put into the tank due to increase in ph?


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## ken31cay

It's probably limestone if it fizzes with vinegar. No limit due to increase in pH. What is the pH of your water source?


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## DJRansome

Consider smooth rocks to head off any abrasion injuries.


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## Darla4022

which other rock would work? i need to increasr ph and water hardness, thats why I was thinking of these. Im just going to put 7-8 of them in center with fake plants, no caves or anything like that for peacock cichlids all male.


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## DJRansome

Unless your pH is VERY low limestone rock is not likely to impact your pH. It does not dissolve fast enough.

What is the test result for KH? If you have a very low pH and KH some crushed coral in the filter would be your best bet. The water being forced through the crushed coral dissolves it a tiny little bit faster than using limestone rocks as your decor.


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## Darla4022

what about pool filter sand, everybody swears by it and says its rounded, I read that its edges are sharp and that is how it filters out debris in the pool filter, and they change it out when it gets round. can you explain, I have pictus catfish, and if its sharp it would injure them, tia


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## DJRansome

It is not round, but you may not want pictus with Africans anyway.

I keep Synodontis with pool filter sand and their barbels are fine.


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## Darla4022

no the pictus are going into another tank, so the pool filter sand is not good then, due to it being sharp correct? im cofused, if not round sharp right? then why is everbody using it, they dont relly know if its hurting the fish then correct? please explain.


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## DJRansome

I read that too, and I have both round substrate and sharp substrate. Absolutely no problems with catfish barbels. In my mind the concern about sharp grains is a fishkeeping myth.

Did you see my comment that their barbels are fine on pool filter sand?

Pool filter sand is HIGHLY recommended.


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## Darla4022

Ok, thank you for your help!


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