Replacing natural live rock with ceramic live rock

[msumatt]

Hi everyone,

I started a little experiment about 4 months ago for my own information, but also to tell others about. I had made my own rock mound out of clay and fired it in a kiln to turn it into ceramic. Each separate rock was made to have at least 20 or more holes in them to accommodate frag plugs. My biggest worry was that there would be impurities in the ceramic that would leach out into the water. I finally took the plunge and replaced a rock mound in my tank with a ceramic rock mound. Here are some photos of the original rock mound and the ceramic replacement. This first picture already has one rock replaced with a ceramic version. It was my way of "testing the waters". Luckily, no adverse effects were observed so I added more rocks later. 9527

[msumatt]

I tested the water before adding the first rock and got the following parameters:
Salinity 1.030
Calcium 350
Alkalinity 6
Phosphate .125
Nitrate 0
pH 8.4

2 weeks later I tested all of the same parameters again and got the following:
Salinity 1.030
Calcium 340
Alkalinity 7
Phosphate .125
Nitrate 0
pH 8.4

Since none of the values were beyond normal fluctuations I have from week to week, I added the rest of the rocks I made. Here's the picture of that below.
9526

[msumatt]

The above was done between mid-February to beginning of March. Here are the parameters for the rest of March and April.
Mid March
Salinity 1.030
Calcium 240
Alkalinity 7
Phosphate .125
Nitrate 0
pH 8.4

End of March
Salinity 1.029
Calcium 300
Alkalinity 7
Phosphate .125
Nitrate 0
pH 8.4

Mid April
Salinity 1.028
Calcium 290
Alkalinity 6
Phosphate .125
Nitrate 0
pH 8.4

End of April
Salinity 1.026
Calcium 250
Alkalinity 6
Phosphate 0
Nitrate 0
pH 8.4

You might have noticed a few things, my salinity was a bit high, my calcium went low and stayed there, my alkalinity is a bit low, and phosphate my be a little high. The salinity took me a while to correct, but more recent measurements show it about where I want it at 1.026. As for calcium, it might be the new rock, but I think it's more that I added many more SPS to the tank as they have been living more than a week, and they are sucking the calcium out of my tank. I've been adding calcium, but not enough to bring it up to around 450 (my goal). Alkalinity has always been lower in my tank, and I've never been able to get it up to 8 or 9 like I would like no matter what I try. And lastly, I can't quite tell the colors of the phosphate test that well. It looks equally likely to be 0 or 25 so I half the differences.

[jimsflies]

Any issues with algae, diatoms, etc?

Its handy to be able to make your own ceramic rock. :)

[msumatt]

Thanks for the question. I actually had more images to upload of how it looks today, but they won't load. For now, the rocks have went from white to mostly dark brown though there are some specks of dark red present. I'm sure the pictures will help. No algae problems, not sure if the dark brown is diatoms, but I can say that color is only present on the new rock, and not on the corals. The dark brown also tends to be part of the succession of rocks I add to the system. They get that color, then it fades over time and is replaced by the pinkish color of calcareous algae. I'll try adding more photos (with closeups) later on this evening.

[dlhirst]

Perhaps your LR would leach out calcium in the past to help replace what the SPS stole from the water? If that were happening, it would explain the pretty dramatic crash of Ca since you replaced all the LR with ceramics. The new pic is all dark at the bottom, so it's tough to tell if there is a sand bed capable of providing the same. But, I like the idea! (I pre-drilled holes in LR so I could stick frag plugs in easily. Wish I had drilled more!)

[msumatt]

You raise a good point that I hadn't thought of. I was going to list advantages/disadvantages that I've learned soon, so I'll be sure to add that to the list. I have about a 2 inch deep sandbed, and though I haven't shown the rest of the tank, as a whole, two rock mounds of similar size are regular live rock, and only one rock mound is ceramic. This idea was actually born from what you described in that I tried drilling holes in live rock, and had mixed success (rocks breaking, or seemingly not wanting to drill). When I got done, I wanted more holes in the rock. Pictures still won't load, so I'll try again when I get back home this evening.

[msumatt]

Here is how the tank looks today. It's now been about 3 months since I started the whole thing. 9529

[msumatt]

bump.....:)

[msumatt]

I had maybe 6 photos to show various close ups of the rocks, but could only get the one above and this one to work here. The cave shown here was really added just for fun and to make the rocks look more "rock-like", but my Randall's goby moved in and has called that it's home for the last moth or so. :) 9533

[msumatt]

So to sum up the last few months of observations of this rock I came up with the following advantages/disadvantages:
Advantages
Can make it is specific to your needs (for example, I made sure a large space was present in the rocks so my lieutenant tang had a better place to sleep at night)
Can make many frag plug holes
They're hollow so are not as much weight on the tank
Another aspect of them being hollow is that smaller "critters" can hide inside the rock to reproduce and keep the fish fed (bacteria could reside in their as well)
If a time comes where I have to cut up the rock, it will be much easier than traditional rock.

Disadvantages
Could be possibly harder to buffer calcium
At least my first attempt, the rocks didn't look as much like rocks as I would like
Plugs I made for the holes tended to get blown out in high current areas
Most plugs needed to be glued in the hole (holes pointing perpendicular to the surface of the tank)

I hope this little experiment will help anyone who might be deciding whether or not to buy ceramic rocks from companies. Also, if anyone would be interested in having some ceramic rocks made, just contact me and I can make some for you.

Any questions, just let me know. :)

[msumatt]

I finally figured out why the pictures wouldn't load. These are a few months old, but I just wanted to show how things had already grown on the rock, and that the corals were doing fine. :) 9711

[msumatt]

Here's one more. 9712