Rock eroding???

[aztoza]

Tank is 3 months old and it seems that my rock is getting more and more holey…can see through in some spots and sometimes a small bit falls off when I scrub with a toothbrush. Alk is 7.7, no urchins just a hermit crab and the rock is Caribsea dry. There are 2 rock islands that I think will be ok, but the rest is epoxied into one big structure…is this normal? Should I look to replace the rock before it completely breaks?

 

[DaJMasta]

How's your pH? It shouldn't be dissolving, but if the pH is low, it is certainly possible. Is your rock aragonite?

 

[Bruttall]

Low PH (not to be confused with DKH) will cause the dissolving of rock containing calcium, like Limestone for example, it is why we inject CO2 into Calc Reactors to lower the PH to start the Limestone dissolving to release the CA and Trace elements.

PH levels of 7.9 to 8.3 are generally acceptable.
DKH levels 8 to 12 I believe are generally considered acceptable.

 

[aztoza]

Low PH (not to be confused with DKH) will cause the dissolving of rock containing calcium, like Limestone for example, it is why we inject CO2 into Calc Reactors to lower the PH to start the Limestone dissolving to release the CA and Trace elements.

PH levels of 7.9 to 8.3 are generally acceptable.
DKH levels 8 to 12 I believe are generally considered acceptable.

Ph is at least 8, closer to 8.3. It is not aragonite rock but very porous and it’s just not being solid. Should I look to replace before it crumbles, or try raising Alk and put in encrusting corals to solidify it?

 

[Mr. Mojo Rising]

Can we see pics? Rocks should not be dissolving.

 

[aztoza]

Sure. These are some erosion spots—deep pockets forming in the first pic, and in the second light shines through in the circled spots.