A question about Texas Holey Rock

[tobraham]

I used to keep Oscars and would dream of keeping African Cichlids. One of my old goals was to have a tank of Mbuna Cichlids and stack it with Texas Holey Rock for them to hide in and possibly spawn. Obviously my interests have shifted towards much, much smaller Cichlids (apistogramma cacatuoides). Today I thought "Woah.. I've been trying to create hiding spaces with clay pots and rock, would Texas Holey Rock work for breeding caves?" Does this rock change the PH in a negative way? Does anyone have experience with Texas Holey Rock and dwarf cichlids?

 

[Mike Wise]

This old geologist knows that there are 2 different commonly available holey rocks. One is mostly man made by drilling holes in a soft volcanic ash called tuff. This is mostly chemically inert. The other is made in nature by dissolving holes in mostly limestone. This, like any calcareous rock, will release carbonates & bicarbonates into the water and hardening it. Yours looks like the latter, but I'm not positive. You could test it. Take a rock and scrape a small amount of powder from it. Then add a few drops of white vinegar (an acid). If the powder 'fizzes' it is a carbonate rock and will harden water.

 

[tobraham]

Thank you for the tip. The picture was just of some Holey Rock I found online, not any of my own stock. Before purchasing this somewhat expensive rock, I'm trying to do a bit of research. I did find a supplier of man made Holey Rock (universalrocks.com) and might just go for that to save on weight in my tank and make sure nothing leaches into the water.

 

[gerald]

A. cacatuoides is one of the more adaptable Apistos (not an obligate blackwater fish) and will breed OK even in moderately hard water. If your source water is soft, limestone will raise GH and KH, but cacatu's probably wont mind. If your tap water is hard to start with, then holey rock wont make much if any difference. If your holey rock is the volcanic type (not limestone) make sure it's not too sharp; fish can get scraped on sharp edges when chasing.