Another noob question

Live rock is effectively two things. It is rock with live bacteria on it that can complete the cycle for a tank. In essence, adding live rock cycles a tank. It is also a home for a handful of creatures, some good and some potentially bad, that'll attempt to live in your tank (in the case of the good ones, they'll form what is referred to as the "clean up crew (CUC)" and help the tank).

Move any live rock, even in an established tank and you'll upset the balance the bacteria live in. Some will die. Whether you even notice this happen will depend on how established the rock is and how big the change is. Typically in the case of a new tank the change (for the rock) has been huge and happened multiple times recenly.


Now the thing about your rock in a cycled tank. Don't worry. You may even use the rock to push the cycle along depending on how much natural die off it has. The bacteria that live on the rock will love the process ("cycling" is in essence their breeding period). The creatures living in the rock may not appreaciate the process much, but it won't nuke them. It may kill some, but there is no avoiding it. Curing your rock (storing it in a separate container until it stabilizes) will do the same thing as cycling the tank so either way they are going to have a rough time. Enough should survive.

the sand you're adding, is it "live" sand? If it is, it will shorten the cycle. If not, you may want to see about getting a cup of live sand from another reefer to seed it to get it going.

Getting the water parameters in check before adding the live rock is the way to go. But once you add it, you will get another cycle. Depending on how much die off there is, you may or may not notice it.

Believe it or not, your tank will go through all kinds of cycles for the first year. But it's the beginning where they're the most dangerous to live stock. So once you think you're ready to add critters, go slow. Give your tank time to adjust to supporting the bioload.

Saltwater cycling doesn't really have a set schedule. It is the same as FW if you start with dry rock/sand. With live rock though it all depends on the quality of the rock to begin with. Fully cured rock may practically instantly cycle a tank. Rock that has been shipped around multiple times and hasn't had much time to soak may take weeks to balance out the die-off with the bacterial colony.

You measure the saltwater cycle the same way as the freshwater cycle. When ammonia/nitrite measure 0 and you have some nitrates. It isn't a matter of whether your rock is alive or not. If your tank cycles fully then you have live rock.



As for the sand. You can use it. I have about 120 lbs of it in my tank with about 10 lbs of aragonite and some crushed up coral/rock. Just keep in mind that your will have two side-effects from using it. You will have one less natural buffer (although it is arguable on how much of a buffer aragonite actually truly is in most tanks) and you will not have a phosphate sponge (arguably a good thing in the long-term, bad in the short-term). All perfectly fine to overcome and adapt too, but things to keep in mind.

Cheaper sources for live sand would be craigslist, ebay, or some of the online places that sell rock. I use cheap sand in my freshwater setups but have always used argo based stuff in my SW setups.

Skimmer isn't required for FOWLR setup, doesn't hurt but I've had no problems running with out one, its something you'll certainly want to consider when/if you decide to start adding corals, nems, etc.

Here is the problem with aragonite and "cheap".

At one point no one cared where the sand came from. There was concern over children inhaling silica dust, even if it didn't really apply past the "open bag and pour" phase of building a sand-box, so some companies had the idea to package aragonite based sand as an alternative. As the aquarium industry grew people started to notice that this stuff was the same as the more expensive stuff sold in pet stores. So the companies that sold aragonite based sand in pet stores bought out the companies that sold aragonite based sand at hardware stores. It is extremely rare to come across it now.

There are effectively no direct alternatives anymore. You may find it online for less then $1 / pound but nothing comes close to the hardware store sand prices. Those are effectively $0.10 / pound.


It is really up to you on whether it is worth it or not. Personally I think there are no shortage of buffers in a saltwater tank and that there are plenty of alternatives for phosphate absorption that don't risk becoming a problem down the line. But it is a factor that everyone should keep in mind. It isn't as simply as one being a cheaper alternative, there are actual tradeoffs.



You don't need a skimmer with just the live rock. But it doesn't hurt to have one either.