Is Live/Dead rock useless regarding filtration?

[sixty_reefer]

As I see it I’m starting to believe it is, especially if we talking about rock with the sole purpose of filtration, in reality what was the last time that anyone suggested for someone to add more live rock as a way to control nutrients? Or for that matter what was the last time that anyone increased the volume of rock into the scape that end up lowering nutrients. I can’t remember in all my time on here to see it accomplished. I have done all those experiments in the past and i know it’s not effective.
In todays times we use macro algae and carbon dosing to manipulate nutrients efficiently and the rock seems to me just a nice way to add some sort of a reef look and a place to add corals although personally I don’t see any advantage on having rock work regarding filtration. Can anyone?

would a system effectively crash if all liverock were to be removed from it? Or started without any liverock?

 

[Lost in the Sauce]

Let's define terms. When I consider "filtration" I am thinking of Cleaning the water ie socks, floss, roller, sponge, skimmer, and so on that is intended to remove particulates from the water before they breakdown or dissolve.

When I think of the Purpose of macro algae, biopellet reactors and such, they are nutrient control devices, not really filtration.

Are we thinking along the same lines?

 

[mdb_talon]

Certainly it plays a big role in the nitrification cycle and the conversion of ammonia to nitrate. Yes other things like bioblocks, etc can fill that void if you prefer. Some surface area is certainly needed to be able to host the bacteria required though. When you speak of lowering nutrients though this is more of the denitrification process and generally speaking live rock is not as effective at that.

While I don't believe the old standard(2lbs rock/gallon) is relevant I would say that yes live rock still plays a massive role in the nutrient cycle of most tanks. This does notean that things like carbon dosing or macroalgae do not play a role.

I would also add that I think forums like these(generally the more serious hobbyists) can become an echo chamber that distorts the "average" person with a saltwater tank. I sell coral at a local store and talk to many customers and can tell you the majority don't use things like macroalgae and the vast majority have no idea what carbon dosing even is.

 

[sixty_reefer]

Let's define terms. When I consider "filtration" I am thinking of Cleaning the water ie socks, floss, roller, sponge, skimmer, and so on that is intended to remove particulates from the water before they breakdown or dissolve.

When I think of the Purpose of macro algae, biopellet reactors and such, they are nutrient control devices, not really filtration.

Are we thinking along the same lines?

It’s all in the same group, just removed in a different way Imo

 

[ReefGeezer]

Almost any substrate will reduce nitrogen compounds via growth of autotrophic bacteria. Properly managed, that alone is capable of managing nitrogen compounds. That's the easy part. However, that does nothing for phosphate or dissolved organic compounds. Heterotrophic bacteria, phyto and protoplankton, and more complex organisms that are commonly imported to the system via live rock, and possibly bottles, can eventually manage these. They may even replace the autotrophic bacteria as users of nitrogen... eventually. As far as actual "filtration", to me, anything that exports organic compounds from the water column can reduce the system's dependence of the aforementioned organisms to manage nutrients. Skimmers come to mind. IMO, carbon dosing in all of its forms is a process that aids in that export and, as a byproduct, provides some food.

I don't use macroalgae or carbon dose. I use a mixture of live and dead rock in the DTand a good sized cryptic fuge, corals, and a not so big skimmer. Sorry for the bad picture but here's a quick pic of the tank today...

 

[sixty_reefer]

Certainly it plays a big role in the nitrification cycle and the conversion of ammonia to nitrate. Yes other things like bioblocks, etc can fill that void if you prefer. Some surface area is certainly needed to be able to host the bacteria required though. When you speak of lowering nutrients though this is more of the denitrification process and generally speaking live rock is not as effective at that.

that’s one of the reasons I come to start to believe that most medias are in a way useless, according to aquabiomics and recent eDNA testing nitrifying bacteria has little to no effect in the nitrogen cycle past a few weeks in the cycle, the main bacteria is living in surfaces and in the water column.

While I don't believe the old standard(2lbs rock/gallon) is relevant I would say that yes live rock still plays a massive role in the nutrient cycle of most tanks. This does notean that things like carbon dosing or macroalgae do not play a role.

I would also add that I think forums like these(generally the more serious hobbyists) can become an echo chamber that distorts the "average" person with a saltwater tank. I sell coral at a local store and talk to many customers and can tell you the majority don't use things like macroalgae and the vast majority have no idea what carbon dosing even is.

Not knowing what it is is much different from not dosing in my view, all foods contain in a way or another a form or of carbon, this is the reason the microbiology of a system changes a lot during the first few months from being set up.

 

[ReefGeezer]

To be as transparent as possible, I guess i do add some things that increase organic carbon and could be seen as carbon dosing. I add small amounts of Reef Energy AB+ and Phytoplankton a couple of times a week.

 

[sixty_reefer]

Almost any substrate will reduce nitrogen compounds via growth of autotrophic bacteria.

Not totally true only in anoxic areas can autotrophic bacteria break down no3 into n2 gas. Thin layers of sand and small rocks wouldn’t be exactly following the criteria for anoxic environment although some small areas may exist.

Properly managed, that alone is capable of managing nitrogen compounds. That's the easy part. However, that does nothing for phosphate or dissolved organic compounds. Heterotrophic bacteria, phyto and protoplankton, and more complex organisms that are commonly imported to the system via live rock, and possibly bottles, can eventually manage these. They may even replace the autotrophic bacteria as users of nitrogen... eventually.

I believe this to be certain in every system that sustain life.

As far as actual "filtration", to me, anything that exports organic compounds from the water column can reduce the system's dependence of the aforementioned organisms to manage nutrients. Skimmers come to mind. IMO, carbon dosing in all of its forms is a process that aids in that export and, as a byproduct, provides some food.

I don't use macroalgae or carbon dose. I use a mixture of live and dead rock in the DTand a good sized cryptic fuge, corals, and a not so big skimmer. Sorry for the bad picture but here's a quick pic of the tank today...

Looking good

 

[sixty_reefer]

To be as transparent as possible, I guess i do add some things that increase organic carbon and could be seen as carbon dosing. I add small amounts of Reef Energy AB+ and Phytoplankton a couple of times a week.

I think the question I’m trying to ask is, would you believe your system would fail if you removed all the rock work from it? Or do you believe that it would just find a way to carry on being cycled without the aid of rockscape?

 

[Spare time]

I think the question I’m trying to ask is, would you believe your system would fail if you removed all the rock work from it? Or do you believe that it would just find a way to carry on being cycled without the aid of rockscape?

I would bet this depends if you have sand or not. Relying on water column bacteria is not a good idea given that many people in this hobby run skimmers. The glass walls of an aquarium is likely not much surface area in regards to bacteria. However, this is one of those scenarios where there really isn't a huge benefit for investigating as a tank with no rocks would be horrible for the animals.

 

[vetteguy53081]

As I see it I’m starting to believe it is, especially if we talking about rock with the sole purpose of filtration, in reality what was the last time that anyone suggested for someone to add more live rock as a way to control nutrients? Or for that matter what was the last time that anyone increased the volume of rock into the scape that end up lowering nutrients. I can’t remember in all my time on here to see it accomplished. I have done all those experiments in the past and i know it’s not effective.
In todays times we use macro algae and carbon dosing to manipulate nutrients efficiently and the rock seems to me just a nice way to add some sort of a reef look and a place to add corals although personally I don’t see any advantage on having rock work regarding filtration. Can anyone?

would a system effectively crash if all liverock were to be removed from it? Or started without any liverock?

You are likely referring to biological and bacterial qualities- In a sense no but do offer buffering purposes. It can however inherit bacteria as it becomes seeded within tank and with exposure to denitrifying bacteria as the pores will accumalate beneficial bacteria

 

[ReefGeezer]

I think the question I’m trying to ask is, would you believe your system would fail if you removed all the rock work from it? Or do you believe that it would just find a way to carry on being cycled without the aid of rockscape?

In my system, I think there must be suitable surfaces for the organisms that process the nutrients to live. Does it have to be rock? Possibly not... if the organisms (like those that normally come on live rock) could somehow be introduced and find enough other suitable surfaces to inhabit. With live rock these days being less porous than in the good old days, that might not be as hard as it once was. However, I don't know of a media yet that is cultured in the ocean like live rock... although, I suppose, the manmade rock is really a "media". That might be a good experiment for @LiverockRocks.

Without the organisms above doing the job, I think the other means of controlling DOC, nitrogen, and phosphate like zeolites, Cheato refugiums, ATS, Cheato reactors, and carbon dosing will do just that... BUT the question is... Do they do so by limiting nutrients from corals and other desirable organisms in the system?

 

[sixty_reefer]

I would bet this depends if you have sand or not. Relying on water column bacteria is not a good idea given that many people in this hobby run skimmers.

Wouldn’t be the same as a quarantine? With the pelagic bacteria doing most of the work regarding nutrient and ammonia oxidising

The glass walls of an aquarium is likely not much surface area in regards to bacteria. However, this is one of those scenarios where there really isn't a huge benefit for investigating as a tank with no rocks would be horrible for the animals.

I agreee that system could look awful without some sort of structure in it although that’s not the point of the discussion.

 

[Nano sapiens]

If you look at live rock just for its nutrient processing capability (as we measure it), then it's not great at this. Per older studies, live sand was shown to be much more effective at processing, which makes sense due mainly to its much larger overall surface area compared to live rock in a typical reef aquarium.

However, there's a lot going on nutrient wise with live rock both externally and internally that should not be discounted. The way I look at it is that live rock's positive influence on a system is largely due to its ability to harbor many different creatures (bacteria, archaea, fungi, periphyton, sponges, worms, etc.) that can sequester and move nutrients up and down the food chain throughout the system. Over time, these interactions naturally tend to balance themselves out and we have what we call a 'mature stable system'.

 

[Spare time]

Wouldn’t be the same as a quarantine? With the pelagic bacteria doing most of the work regarding nutrient and ammonia oxidising

I agreee that system could look awful without some sort of structure in it although that’s not the point of the discussion.

A proper QT should have biofilter and cycling bacteria added imp. My second comment was more or less saying that regardless, the application of the question is almost trivial since no one directly uses rock as a filter for nitrate and phosphate (albeit it was more popular to do so for denitrification with previous styles of rock in the hobby), but rather as a home where things that could use nitrogen sources and phosphate (as well as eat crud) can live. In tanks with very little rock, it may be beneficial to add more so that more critters can consume waste products and thus keep the water cleaner

 

[JNalley]

Filtration:

Mechanical: Floss, Fleece (and others)
Chemical: Resins, GFO (and others)
Biological: Rock, BioBalls (and others)

Dual purpose (Mechanical+Chemical): Carbon
Dual purpose (Mechanical+Biological): Sponge

Plenty of other filtration materials/media fit within the above categories I don't have time to think of and name them all, but each serves a purpose in filtration, so the answer, in my opinion, to your initial question is: No, it is not useless. It provides a surface for bacteria to live on, increasing the colony size and thus the amount of Ammonia you can process into nitrite and, eventually, nitrate. However, the bacterial population is only going to be as large as the food source allows, so there comes a point when adding more rock/surface area is unnecessary.

You can also replace all rock with different surface areas, such as sand, bio-balls, ceramics, and any porous structure that can survive in a marine environment will work really. At that point, rock *could* be useless.

However, you allude in your post about using macroalgae and carbon dosing to manipulate nutrients, this type of filtration is targeted at Nitrate -> Nitrogen gas, not Ammonia -> Nitrate (which is what rocks mostly help with). The bacteria needed to transform Nitrate into Nitrogen need an anoxic environment, in the ocean, this is handled by bacteria deep in the sand. Some of these bacteria do live deep in the rock, and this is what carbon dosing excites (I think), but a deepsandbed is a much better environment for them, at least according to some articles I read within the last few years.