125G Fish Only Tank without live rock?? Opinions Please

[Glendower]

Ok guys I am posting this idea here as I have heard a lot of conflicting opinions on this subject. Still fairly new to the hobby. I currently run a 30g FOWLR Tank stocked with clowns, a royal gramma and a chromis.

I am planning in the future to upgrade to a 125g tank, then converting the 30g into a hospital tank so I can include tangs and angelfish.

I am interested in the idea that it may be possible to use cannister filtration such as a fluval fx6 rather than live rock. I would include a scape with some dried reef rock to create interest and keep the fish as happy has possible. I love a simple and clean looking tank and for me it's all about the fish, while I appreciate corals I think for me keeping the parameters in check and the extra maintenance required would be more stress than it's worth at this point. Plus some of the fish I am interested in are known to damage corals.

So my question is, in a fish only tank will a cannister like an fx6 combined with consistent weekly water changes of 25% be sufficient to keep a tank of this description in good health? Or what kind of additional filtration would be required? Thanks for all opinions! I have heard that bio balls are actually more efficient at harbering the nitrifying bacteria than live rock and although they are nitrate factories is this really such an issue in a fish only tank?

 

[Tripod1404]

You can have a large sump and keep you live rock there or use some type of filter like you described.

But I would worry more about how the fish would respond to not having rocks more that the filtration. Most of the reef fishes live on rocky environments. Reefs are not open/empty sand beds and few fish in the hobby comes from open sandy environments. They need some rocky substrate to feel comfortable, to graze on, hide under, etc. Without any rock (unless you want to have PVC pipes in you DT), they will be lot more aggression and behavioral problems.

In a sense, it would be like keeping a spider monkey on a empty grass field.

 

[d2mini]

IMO, one of the best things about saltwater tanks is how live rock makes things so much easier/simpler by providing natural filtration.

At the very least, I'd want a very large sump full of live rock, and a fuge with cheato.

 

[Glendower]

What it doesn't simplfy though is the treatment of parasites, you could treat the tank with copper and just pull it out afterwards with a massive water change and placing carbon in the cannister. If you have live rock on the other hand then the "live" part of the rock would die off right?

I just don't like the idea of an ich outbreak and having to transport all the fish into a seperate tank for two months, it would be a massive advantage to be able to dose the main tank.

Also as for recreating the rocky reef environment, that could be recreated artificially with realistic rock replicas instead of the standard 125lbs++ of live rock.

 

[Joshua I.]

Seeing how it's fish only your totally fine you can treat your tank directly if anything comes up I personally love the canister filters! Best part is you can buy really nice dry rock and place it in with some really nice white sand it makes the fishes colors really pop!

 

[ReefMaster48]

As others said, there is a number of issues with not using any rock. One being the filtration. Nature is always the best filter. And two, being the habitat. You NEED something for the fish to hide, graze, and swim around. Not being smart here, but how would you like to be kept in a empty box? The fish need spaces to hide, sleep, and interact with. I would bet that a tank with zero rock would be full of boring swim patterns, disease from stress, and premature death.

A canister for a 125 will not cut it. Your going to need a sump, especially if there is no rock in the tank. Ignoring the filtration side, there are ways of getting your DT to run with little rockwork. One of the scapes I thought may be cool would be one of those big shipwreck decor pieces you see in petsmart and petco. (i would have numerous pieces of rocks) However, you could do something similar with little rockwork. Nevertheless, you have to be careful with such decor, as not all is SW safe. But that brings us back to filtration, which you would then need a sump full of rock. Or at least a bunch of MarinePure 4 in plates.

 

[sde1500]

What are we defining as live rock here? Because you said you don't want any, but then said you'd put reef rock in the tank? If by that you mean just dry rock like pukani or something then that's still filtration. I would want at least some rock. Certainly don't need a massive pile of it. And a canister filter should be fine to provide the rest. My in-laws run a tank like that just fine. Always love newbies dealing out absolutes to others lol.

 

[Glendower]

As others said, there is a number of issues with not using any rock. One being the filtration. Nature is always the best filter. And two, being the habitat. You NEED something for the fish to hide, graze, and swim around. Not being smart here, but how would you like to be kept in a empty box? The fish need spaces to hide, sleep, and interact with. I would bet that a tank with zero rock would be full of boring swim patterns, disease from stress, and premature death.

A canister for a 125 will not cut it. Your going to need a sump, especially if there is no rock in the tank. Ignoring the filtration side, there are ways of getting your DT to run with little rockwork. One of the scapes I thought may be cool would be one of those big shipwreck decor pieces you see in petsmart and petco. (i would have numerous pieces of rocks) However, you could do something similar with little rockwork. Nevertheless, you have to be careful with such decor, as not all is SW safe. But that brings us back to filtration, which you would then need a sump full of rock. Or at least a bunch of MarinePure 4 in plates.

As one of the other posters said, I would create a good scape using dry rock so they would have hiding spots and obstacles.

You realise a FX6 cannister is rated for tanks over 300 gallons usually right? And bio balls/rings are proven to be more efficient at harbouring the nitrifying bacteria than live rock. So why is the Berlin method so absolutely endorsed above all else by some veterans even in the case of fish only tanks? I would utilise a skimmer for good measure as well. Would I even need a sump with a HOB skimmer+FX6?

 

[Bronx19]

Place a few sponges in the sump, chaeto, skimmer, good to go.

You don't need anything in the tank itself unless you're keeping fish that need cover.

 

[Tripod1404]

As one of the other posters said, I would create a good scape using dry rock so they would have hiding spots and obstacles.

You realise a FX6 cannister is rated for tanks over 300 gallons usually right? And bio balls/rings are proven to be more efficient at harbouring the nitrifying bacteria than live rock. So why is the Berlin method so absolutely endorsed above all else by some veterans even in the case of fish only tanks? I would utilise a skimmer for good measure as well. Would I even need a sump with a HOB skimmer+FX6?

Because of the reason you listed. They are better at harboring nitrifying bacteria than live rock. Plus unless they are cleaned very often, they trap a lot of waste, something that cannot happen with LR. Together these cause excessive nitrate production. Nitrate is not toxic for fish. I think some public aquariums have nitrate levels close to 1000 ppm. But it would causes algae and white slime even for a fish only tanks.

But ultimately I dont think a canister filter is a lot different than a small sump with high flow as long as kept clean. Good think about sumps is you have extra water volume, and you can hide your equipment. Aside from that they are not something that is absolutely necessary.

 

[Dmorty217]

Canister filter won't cut it. You could do a sump full of Sera Siporax and that would provided the bacteria space you will need. You would need a large bead or sand filter if you don't want a sump

 

[Crusty Old Shellback]

Any rock you put in the system, be it tank or sump, will eventually become live rock as the different bacteria will inhabit it.
As stated, a canister filter alone will not be enough.
You need places to harbor the bacteria that constitute the nitrogen cycle, the life blood of any tank.

 

[Glendower]

Any rock you put in the system, be it tank or sump, will eventually become live rock as the different bacteria will inhabit it.
As stated, a canister filter alone will not be enough.
You need places to harbor the bacteria that constitute the nitrogen cycle, the life blood of any tank.

The amount of posts totally contradicting each other in this forum and hobby in general is astounding. You have just said that a cannister will not be enough as there won't be anywhere for the nitrifying bacteria but then others have said it will actually overproduce nitrate due to it's superiority at harbouring the bacteria.

I don't mind valid reasons being given for why live rock is better but some of these here are total misinformation which will spin the head of anyone not savy enough to realise it.

I am concerned about the potential algae issue from high nitrates but will be using media in the cannister to try and control that as well.


Have you ever stopped and asked yourself how freshwater tanks manage to have a nitrogen cycle without live rock???

:debi:

 

[homer1475]

The amount of posts totally contradicting each other in this forum and hobby in general is astounding. You have just said that a cannister will not be enough as there won't be anywhere for the nitrifying bacteria but then others have said it will actually overproduce nitrate due to it's superiority at harbouring the bacteria.

I don't mind valid reasons being given for why live rock is better but some of these here are total misinformation which will spin the head of anyone not savy enough to realise it.

I am concerned about the potential algae issue from high nitrates but will be using media in the cannister to try and control that as well.


Have you ever stopped and asked yourself how freshwater tanks manage to have a nitrogen cycle without live rock???

:debi:

It has nothing to do with the power of the nitrifying bacteria creating nitrates in a canister filter. The nitrates come from the detritus that settles within the canister, and breaks down into nitrates. They work just fine if kept clean(like weekly cleanings). Even filter socks in a salt setup can become nitrate factories if left in the system to long.

FW filters typically throw away all the media in a filter when replacing them(carbon, and/or filter material). Effectively throwing away all the beneficial bacteria. Nitrifying bacteria will populate any hard surface(IE substrate, decorations, tank walls, filter media, etc), that is how FW setups do it without LR.

You don't really need rock, just some large surface area places for nitrifying bacteria to populate. LR is typically the go to in a SW setup, but aside from the bacteria populations, most of the fish we keep tend to populate the reef where there are massive amounts of rock and dead coral skeletons. In essence we try to keep our inhabitants environment more to what they are used to in the wild.

 

[sde1500]

You are putting rock in the tank, so that will become live rock eventually. That plus the HOB skimmer and canister filter you should be fine. I'd be interested to hear why people say you won't be. Rather than just make a statement, imparting knowledge about why the plan won't be enough would be nice.

 

[sde1500]

Because of the reason you listed. They are better at harboring nitrifying bacteria than live rock.

You do know we WANT that bacteria in the tanks right? That is the same bacteria that is in the rock that is part of the bacteria cycle breaking down ammonia.

 

[Dmorty217]

Canister filters are made for freshwater tanks. Bead and sand filters are made for saltwater tanks. Look at any tank that is full of coral and thriving, you won't see a canister filter under the tank. People used canister filters in the infancy of the saltwater hobby back in the late 60s/ early 70s. I believe Julian Sprung's first tank used a canister filter

 

[Crusty Old Shellback]

I used a canister filter on my 400 G tank in the 2000's. :spin1:

But that was as a supplement to my filtering system. I also ran a swimming pool filter with just a sock in it to trap deuteris.

I'm not saying a canister filter won't work, I'm saying a canister by itself wont work, which is what the others said. I never said it would not harbor bacteria.
And if cleaned on a regular basis, most of the bacteria would be washed out or thrown away.

And I'm one of those guys who had a SW tank back in the 70's with a HOB filter and undergravel filter. :wavehand:

And every FW tank I ever had had some type of rock in it, which became live rock harboring bacteria.

 

[jmm]

The tank and the decorations in the tank will become "live." If the rock is never to be re-used in a reef tank, you can copper the tank in place.

The canister filter, especially a large one, will also become "live." It needs to be cleaned fairly regularly and for a lot of people that is a chore they put off for a long time. The detritus it accumulates increases the bio load on the tank. That opens up the possibility of bacterial and viral diseases. Also, there needs to be some surface skimming or you will have a film on the top of the water that blocks oxygen exchange.

 

[mcgyvr]

The amount of posts totally contradicting each other in this forum and hobby in general is astounding.

Shh... Thats one of those things we don't discuss in fight club..