You knew you should have declined. But someone in the reef club was selling a huge stack of
live rock for a super cheap price. A super good deal. Right when you were already preparing to
set up and stock that old empty system.
But this time you were going to try starting with dry base rock. Especially after the last tank,
which had issues with cyano, hair algae and glass anemones from Day One (well, at least right
after adding the wet live rock). But hey, you saw some pictures of the tank that it all came from,
and it looked good. And it’s already cycled, you said to yourself. And it’s already got lots of
As you now had live rock waiting to get picked up and placed, you hurriedly put that old system
back together. In little time your tank was flowing with seawater, lights shining bright, and piled
high with rock. With all that mature, fully cycled live rock, there was little time before you began
stocking corals. One here. One there. Another, even pricier piece here… A yet pricier piece
there… After a few weeks, the first of several pests and plagues would emerge.
A thin, golden-brown film that spread across the glass, sand and rock surfaces signaled a
benthic diatom bloom. No worries, you thought; you shrugged it off saying, that’s normal and it’ll
go away. Most of it went away. But just after that, a little bit of green stringy stuff started to grow
from the most brightly lit pockets in the rock surface. Crap! There wasn’t much of that stuff–yet–
but you already knew what it was. You saw that before, just like the reddish maroon slime that
started to cover rocks near the bottom of the tank. But your heart really, finally, totally sank upon
first sight of that first teeny weeny baby anemone–a glass anemone. Then the coral-eating
You know it came from that dirty live rock. All of it did.
When the last of the corals died, the tank went back into the garage and the rock went straight
to the garbage.
Dry as a bone
Pests can turn your hobby into a chore. Avoiding them is very much preferable to dealing with
them. This is why good aquarium biosecurity measures are so important. Just like practicing
quarantine, buying only captive-bred, etc., the use of dry live rock is good biosecurity.
Wait… so if it’s dry, how can it be “live?” In this case, the term live applies because the rock is
excellent habitat for beneficial bacteria (and copepods!) as well as desirable forms of crustose
algae. And because it is easily seeded with these organisms.
The usual first concern with dry base rock is with cycling. You may rest easy tonight because
initiating and sustaining the nitrogen cycle with dry aquascaping material is simple as toast. First
of all, there is (unlike wet live rock) no die-off to account for. This makes for a much more
controllable cycling process and also for considerably cleaner starting waters. One can seed
with specially selected strains of nitrifiers using a bottled inoculant such as Fritz-Zyme
TurboStart 900. A big heap of dry live rock (and/or biofilter medium) plus a healthy dose of
nitrifying bacterial inoculant can get a system fully cycled and safe for livestock in less than a
week! What’s more, such bottled products are completely safe and easy to use.
Wondering how to feed the starting colonies of bacteria in a fresh system? We suggest a fine,
inorganic product such as NitroCycle. This product allows for fishless cycling, meaning it is
unnecessary to task a cheap and hardy (though oftentimes very short-lived) fish with initiating
the cycle. It is inorganic and therefore will not degrade water quality as will organic alternatives
(e.g. dead krill).
Now is also a good time to add nitrate-removing bacteria such as PNS Probio™.
It is even possible to seed those beautiful crustose algae. Using ArcReefs’s ingenious live
product Coralline Algae in a Bottle, one can quickly turn the crisp, clean white of dry rock into
bright pinks and purples. You can even select your choice of color (or pick both)!
Oh, but you’re a stickler for natural reefscaping materials? Then check this out. AlgaeBarn’s
trusted rock supplier sources its dry live rock sustainably from the remains of an ancient coral
reef. Yup, so it’s composed of the very same stuff that live corals grow on in the wild: The
skeletons of dead corals. Really can’t get more natural than that. Or sustainable!
We shall conclude by recalling one of the very best things about dry live rock: It’s totally and
completely pest-free. No weird bad bugs. None of the bad algae or bacteria. No bristle worms.
No significant possibility of disease transfer (even fish parasites can hitchhike on wet live rock).
Pull that old system back out from the garage and start one more time with dry live rock for your
new reef base. Once you go dry, you’ll never say bye!