Cycling A Marine Tank

[CezzaXV]

Hello everyone!

I'm coming to the end of the process of converting my freshwater tank to marine. It's a 155L tall tank, plus a sump. I was a very active member of these forums when I was freshwater but signed up to a dedicated reef forum when I went marine. I've had some good advice so far, but every time cycling is brought up everything turns to madness, as it seems to be a very controversial issue! As such it's been very difficult to get impartial advice, so here I am.

I bought 8kg of live rock from an established system, and 11.2kg of rock from the LFS. It was my understanding that you should wait to see some die off from your rock which will create ammonia, then I wait for it and the resultant nitrite to get down to zero and stay there, then my tank is good for a few fish. I waited eight days and had not seen any ammonia or nitrite at all, so made the decision to add 0.25ppm of ammonia on the following basis:

1) If the bacteria were already there processing the ammonia/nitrite too quickly for me to see it, then they'd chew through 0.25ppm in no time.
2) If my dose was eaten very slowly, it would suggest there was not very much going on, and too little for me to cycle.

As it happened, it was a good few days before anything happened and my ammonia went down to zero, so I'm glad I added it. I've since added another 0.25ppm and hope to see it process more quickly this time, but I'd like some advice on this without getting flamed. I'm not completely sure of what I'm doing, and while it makes scientific sense to me to fishless cycle it in a similar (though not identical) fashion as I would in a freshwater tank, but resources about this online seem scarce and I want to make sure I'm proceeding in the right direction.

Any advice greatly appreciated.

 

[Donya]

If the rock is well-transported then you won't see cycling spikes. The most common scenario is to see spikes, but if the rock was well kept at the store (and kept for a while after arriving there) and it didn't spend very long in the car then it's easy to have no spikes. At the same time, taking a few days to naturally remove 0.25ppm of ammonia actually doesn't sound outlandish to me. If you get an ammonia spike due to a dead animal in a marine system, it doesn't go away instantly. So, what you probably just simulated is the death of a fairly sizable animal in a young system and saw the normal results of such an event. You may see an increase in the rate that the ammonia goes away if you repeat the dosing regularly, but the only possible upside to that would be that you might be able to stock faster (but I still wouldn't recommend doing so, since rushing is usually bad news with marine life). Additionally, once you stop dosing ammonia, your bio filtration may eventually end up right back where it started if the food you're adding doesn't create the same amount of waste, so I don't see any advantage to dosing before stocking. Normally with LR that is rich in life it's better to actually add solid food of some sort (pellets, meat, etc.) to feed the hitchhikers first and let the nutrients start higher up. One of the reasons to stock slowly is to allow the ecosystem to catch up with the changes.

 

[CezzaXV]

Thanks, that's the best answer to my question I've received yet.

Obviously marine fish are pretty expensive, and as many of them are wild caught I don't like to think that I might add them to my system before it's ready. They are too beautiful and have come too far to see them die an ignoble death in my bedroom. As well, marine fish are much more sensitive to change, and if my water turns bad because it wasn't ready, I'm not going to be wanting to do massive water changes like I would in a freshwater tank.

Other than my CUC, my stocking plan is to start off with two ocellaris clownfish for the first few weeks to establish that I can successfully keep marine fish alive and build it up after that. I've not seen any hitchhikers in my rock other than a single tiny snail, plus the zoas. In a freshwater system I would be quite happy to dose up to 4ppm and get it down to a reasonable processing time from there. Doing that in a marine tank would be going overboard and may harm any hitchikers I've got that are still hiding in the rock, but I'm wondering what would be a reasonable amount of ammonia to dose and how long it should take to process it before I should be looking to add my initial stocking. I'm not worried about breeding too much bacteria and then having them die off due to lack of food source, as it's better than having fish die on me because I didn't dose/wait long enough.

Every guide I've read tells you when the spikes go down to zero you're good to go, but as I didn't have any spikes I'm not sure how I'll know when my tank is ready for fish.

 

[Xraymark]

If your LFS rock was cured and there wasn't much time getting the rock into your tank, then there probably was little die off in between.  Hence no ammonia spike.  No need to add amonnia.
 
Wait for some diatoms and start adding a few CUC. 

 

[eaglesaquarium]

Thanks, that's the best answer to my question I've received yet.
 

 
That's Donya! 

 

[Donya]

Honestly I do not think adding ammonia in any amount is the best way to go with a marine setup. Slow is good, make no mistake about that! It's the source of the nutrients that's the problem. If you want to wait, add a raw prawn or scallop and let it decay. It will give you ammonia to keep the bacteria going and you will feed more animals that way. I guarantee you there are some in there you haven't seen yet, and even things like small Amphipod species and other scavengers are worth keeping to maintain diversity. Having just essentially forced a cycle on your tank, you should be ready for CUC as soon as you see zero ammonia/nitrite and nitrates under 10ppm. Diatoms may or may not happen with rock from established systems. They can also happen almost at random during a tank's early maturation (I say "almost" because there's always a trigger like an increase in silicates, it's just often hard to pinpoint the reason). 
 
In a water volume of this size, two small clowns fed once daily will be very little impact. However, as Xraymark said, CUC first and feed the CUC if you want to wait (or if the rock is already pretty barren). Biodiversity on live rock is worth maintaining, and you absolutely will start to lose that if you spend a long time just adding ammonia to the tank. The rock you got from an established system would be most subject to that sort of gradual decline. That said, it's not impossible to do a very sterile, undiverse marine tank, and some people do use live rock that is bacteria-cultured only (not cultured in the sea) to avoid undesirable hitch hikers. Those systems end up being very sterile and are often specialized, like for rearing young sea horses or something super-fragile where even some normally innocuous animals can undo the whole thing. Personally I have found biodiversity of LR critters invaluable to overall marine tank stability. 

 

[CezzaXV]

I've got some brown stuff on my sand. My knowledge of different types of algae is pretty poor, but I've done a Google image search and it looks like it may (or may not) be the beginnings of diatoms, but perhaps someone with more knowledge on the subject would be able to shed some light there.


I ended up redosing up to 0.25ppm using bottled ammonia just because I had it to hand, but I admit that I am kind of bodging my way through. Whenever I google the different methods (adding bottled ammonia, adding something to rot etc) it seems there are pros and cons of all of them.

I'll wait to see how long this next dose of ammonia takes to go down to zero again (I wouldn't have thought it would take more than a few days), and as of last night my nitrate was 1ppm. I'm perfectly happy to add a CUC at that point, and I'm also perfectly happy to add fish at that point as well, but I don't feel comfortable doing either unless I know why I'm doing that and why it's fine to do so.

 

[Donya]

Whenever I google the different methods (adding bottled ammonia, adding something to rot etc) it seems there are pros and cons of all of them.

 
I have never heard or read of people adding ammonia to marine tanks with live rock. I've read tons of ways of setting up marine tanks and never seen that one, so to be honest I really wonder about the reliability of sources that suggest such an approach. I would ask for links but I suspect many of these weird things will be coming from other forums where linking would be against the rules here. However, if you have non-forum articles advocating the ammonia method with live rock, please post them since something really sounds off with that method. Internet being what it is, in addition to good material, there is also plenty of bogus stuff. 
 
Ammonia-only stress tests are not going to give you an accurate indicator of how the system will perform under normal conditions when established, because you have not created the whole ecosystem yet. Like I said before, you have simulated a large animal dying and decaying - like what would happen if a large sea hare crawled off under a rock to die and wasn't eaten. That sort of thing can crash even a well-established, well-filtered system, since the ammonia doesn't go away fast! I can tell you that from direct experience, and there is no way around frantic WCs in those scenarios. But, you will not be adding large animals right off the bat and will likely want to stay away from animals that would risk that scenario anyway. Plus, with the ecosystem in place you will have the flip-side that small animal deaths may even go undetected when scavengers consume the body right away.
 
Now, there are also people who do NOT use live rock in their systems, and it would surprise me a lot less if some of them advocated ammonia in with dry rock or even rock-less systems. If you start with dead rock, particularly dead rock that was formerly live, it's common to subject that to some pretty extreme stuff like HCl baths before by recolonization since there is no life to preserve, so ammonia wouldn't harm anything. However, the recolonization is still more commonly done with a LR seed and raw seafood for the animal reason rather than ammonia.

 

[Xraymark]

Your freshwater, fishless cycling instincts are kinda getting in the way. You don't fully stock a reef at the start.


Think of it like a fish in cycle. Every time you add to the bio load your live rock increases is bacterial colony. That's why we add slowly stocking wise in a reef. Live rock is very efficient at responding to this increase in bio load so there shouldn't be any measurable rise in ammonia etc. As long as its done slowly your livestock will be fine.

That looks like diatoms. Once your ammonia and nitrites zero, add some CUC. You may need to feed them initially as well. That will help increase your biological filtration as well.

 

[CezzaXV]

Thanks guys, it's nice to have someone explain it to me. I don't plan on whacking all my stock in right away, but I do want to make sure that my rock can support my initial plans, which is the CUC and the two ocellaris clowns.<br /><br />So as soon as the ammonia goes down, I'll happily add some creatures of some description. Are we sort of agreed on just the CUC? You reckon I should be looking to add something to rot? I'm told a prawn is the way to go.

EDIT: This is the best website I've found which describes methods of cycling rather than just the science, but it doesn't explain what to do when you just never have any spikes from your live rock. http/www.seahorse.org/library/articles/cycling.shtml

About.com also describes the bottled ammonia method.

 

[Xraymark]

Don't add any prawn to rot. That's only for dead rock as D has commented on.

Add some CUC. Feed them sparingly. They normally feed of algae and left over food fish have not eaten.

 

[Xraymark]

From your reference and the position you are most likely in.

Then, finally, there is cured live rock. Fully cured rock that is quickly placed into your tank with minimal transportation time, such as from your LFS (local fish store) to your home, may 'instantly' cycle your tank. The beneficial bacteria groups are already there in good numbers with no die-off to trigger ammonia spikes of any significance. With fully cured live rock you may never see the typical cycling progression of ammonia —> nitrite —> nitrate. Your levels may initially read — and remain at — zero, even while you are slowly stocking your tank.

 

[Donya]

Don't add any prawn to rot. That's only for dead rock as D has commented on.

 
It's also appropriate for live rock that is going to be left to sit for ages with no animals (or even with CUC, since they'll eat the meat). Of course not a giant huge bunch of meat all at once though, but rather little bits. Without something like that, the rock will slowly die-off if left to stand a long time. Feeding rock with bits of meat is a trick I've used more than once when I know a tank is going to have to sit unoccupied. So, if this tank is going to sit for more than another week or so without any animals being added to it then I would advocate adding a small piece of something to keep it ticking. If CUC is going to go in, then it should go in when the ammonia/nitrite are gone and nitrate is low.
 

EDIT: This is the best website I've found which describes methods of cycling rather than just the science, but it doesn't explain what to do when you just never have any spikes from your live rock. http/www.seahorse....s/cycling.shtml

 
This site is offering some general info, but it's worth noting that it's a seahorse site and seahorses are pretty specialized in the marine world. That's probably why the non-LR method is even mentioned at all, since the idea of a truly fish-only tank is considered totally obsolete these days except for very specialized cases where LR poses some sort of more direct problem (e.g. animals would destroy it, can't risk hitchhikers, etc.). Seahorse people sometimes use special bacteria-only cultured rock because some normally innocuous hitchhikers can cause havoc with such fragile livestock. Similarly, I'm aware of people avoiding LR altogether for breeding projects. It does look like the site is clearly separating the LR vs. ammonia methods, which is pretty much what I described. When you have no spikes, add some CUC animals and start feeding is the general way to do it for tanks that will have a CUC (some seahorse tanks I've seen do not). The safest way to build up the CUC is slowly after that on an as-needed basis.
 

About.com also describes the bottled ammonia method.

 
It's also far from the best pick as a resource for for any sort of fish advice. 

 Most of the marine info I've read there is either out-dated or has problems of some sort. For example, this is absolutely the WRONG thing to do on many levels, but there is on the Internet nevertheless:
 

Add some hermit and/or true crabs instead. They are pretty hardy animals, rather inexpensive, and will cycle your tank just as well as fish do.

from http/saltaquarium.about.com/cs/bionitrogencycle/a/aa042403.htm (is that the page you saw? It mentions the ammonia method)
 
I don't even know what to say about the bit at the end where they mention using human excrement to cycle a fish tank...just...don't. Not a good site for fish info.

 

[CezzaXV]

Thanks guys. I had doubted the About.com credibility as there is a fair but of info I know to be bad, but thought I'd mention it. There are a hell of a lot of sites that are those very general info sites, but it's difficult to find much that goes into the kind of detail I'm looking for. I had no idea how to tell that those zero readings meant it was being processed and not just that there was nothing going on, but I guess it does mean there is stuff going on even if it took a few days. Glad I did it now for peace of mind, even if it was a bit unorthodox.

I've not tested my tank tonight, as I decided to wait til the the morning so I can check the results in natural daylight, but say I tested tomorrow and it was zero, what would be the advantages of adding just the CUC as opposed to (or as well as) my first two clowns? It was my understanding from my freshwater days that the bioload from inverts was pretty negligible, but do correct me if that is not the case with marine. My plan for my CUC is one or two cleaner shrimp, some peppermint shrimp, several hermit crabs and snails of some description.

I have aiptasia, hence the peppermint shrimp, though I've not done any real research on them. Also, I wouldn't necessarily (and don't know if it would be wise to) add all that right away. I'm also very much not limited to what I've written above.

Sorry if it's silly/paranoid questions, but I just don't like the feeling of not being sure what I'm doing and why.

 

[Donya]

what would be the advantages of adding just the CUC as opposed to (or as well as) my first two clowns?

 
The purpose of a CUC is to remove algae and uneaten food. When you get your clowns, you will feed them and they won't eat all of it (some clowns and other fish may even refuse food for the first few times its offered until they settle in), so the uneaten food will go blow about and decay unless it gets eaten by something. Unless your rock is already full of critters, you are likely to get excess waste and nutrient problems if the uneaten food isn't consumed fairly quickly*. It's better to build the ecosystem bottom-up than top-down for stability. If you add everything at the same time, you are adding a bigger bioload (less stable) than if you add spaced out over a longer time. 
 
 

It was my understanding from my freshwater days that the bioload from inverts was pretty negligible, but do correct me if that is not the case with marine

 
It depends on the invert in question and the natural food supply in the tank. Part of the CUC food supply will be naturally occurring in the tank. On the other hand, the bioload of a specialized invert that has to be fed will be, well...like feeding pretty much animal that volume of food. So, for example, not all herbivorous inverts are low-bioload. Animals like large sea urchins and sea hares can be high-bioload in some tanks because of supplemental feeding needs if/when a the tanks own food sources run dry. These animals will be treated like low-bioload CUC in one tank and higher-bioload ornamentals in another.
 
Even in fw it's not true that inverts are always low-bioload. Apple snails are a category that cause a lot of bioload problems for people because of that assumption, since they are really quite messy animals when properly fed.
 
 
 

My plan for my CUC is one or two cleaner shrimp, some peppermint shrimp, several hermit crabs and snails of some description.

 
Cleaner shrimp don't really act as CUC. They will eat some leftover food but are also fragile and so should go in the tank after it has matured a bit. Same for peppermints even though they are more active at picking over rocks. I would wait to add those until after the fish even. Make sure you drip acclimate any shrimp slowly (test bag water salinity and tank salinity beforehand to know how big the difference is) and the other CUC as well for safety. Shrimp deaths within a few days of being added to a tank are common due to rushed acclimation and/or fluctuations in water parameters. 
 
*EDIT: you'd basically be doing the equivalent of throwing the piece of prawn in to decay if the food isn't eaten quickly, which is not what you want once larger animals are in the tank.