Live Rock for filtration. Good or Bad?

[Vafik]

From time to time when someone is discussing filters for a reef tank people are steered clear of using them for bio filtration.

Now correct me if I'm wrong ,and I might just be, but wouldn't having a filter for bio filtration just be a plus for a reef setup? Seems like relying on some live rock and live sand is not the best option. If these two ways of bio filtration are so great then why do so many ppl have nitrate or nitrite or other bio tank problems? I think it's b/c relying on LR and LS is like putting a sponge in your tank and hoping it takes care of all the filtration for you with little to no water movement through it. Hell when someone does but a HOT filter of some kind they put a few pieces of LR rubble in it. Now wouldn't a sponge or a few bio balls have a better growing area for beneficial bacteria then a few pieces of rock rubble? Now I'm sure LR is great b/c it's so porous but with out a strong current moving through the rock entirely then your LR is doing very little filtration for you at all. And for those that say they have more then enough current in there tank I'm sure they do, but I'm also sure that water is moving around your rock and not completely through your rock. Again I'm sure it takes care of some of your filtration but not enough if you have to run a sump or refuge with some macro or a phosphate reactor and a skimmer to filter your tank further. Look at some of these tanks that people have with over 100 lbs of LR and still are having problems with bio load. Running water over the surface of a rock is only going to filter so much water for you. And not to mention that beneficial bacteria colonies do better when kept in the dark and not in high light. So when you have 200 + MH or PC lighting shining down on your LR your creating a poor environment for BB colonies. Running a canister filter for bio seems like a really good idea to me but these are just my $.02
I would like to hear from more of you so chime in please and let me know if you disagree or have another theory. Again I think I might be on to something b/c this is how I felt about the whole watts per gallon rule when it was so popular. Just made little sense to me and I was right about that How could something like light be measured as a soluble? Well anyways I would like some feed back. Thanks.

 

[skipm]

You are right that the filter is more efficient at processing waste and that is where the problem lies. By using LR as the filter the process is a little slower and this gives time for the waste to be used/eaten by other tank inhabitants. Nitrate is the end of the regular biological cycle, in order for nitrate to be further processed you need anaerobic bacteria and the only place you usually find them is in the center of larger pieces of LR. Filters that employ biological filtration are very aerobic (having oxygen) so they cannot process nitrate to anything else, they process ammonia to nitrite to nitrate. When you see nitrite and ammonia levels above zero that is an indicator of a problem whether it be in a reef with LR on or a large freshwater tank with a huge biofilter. If you have a slower biofilter like LR there is some time for things like crabs, starfish, shrimp and other scavengers to utilize waste products as food, when you have a biological filter like you are talking about the waste gets broke down before they have a chance to utilize any of it. The more waste used a food the less that gets converted to nitrate so your nitrate levels stay hopefully lower and easier to maintain through regular maintenance and water changes.

 

[Vafik]

Ok so your saying the clean up crew, well at least some of them use waste as food. Now are you talking about fish waste or amonia? I thought it was fish waste and left over food that these organisms use for a food source. If thats the case then your buying a clean up crew to do the job of a bio filter. So why not skip the clean up crew or limit it to just a few oranisims so your not relying on them to clean up waste. This way you could have a much stronger bio filter in place which would me less maintness and better more stable water chemistry. Chime in again as I'm liking were this debate is heading

 

[skipm]

I am mainly talking about fish waste and leftover food and detritus. If these are processed with a traditional biofilter they will be broken down into ammonia quite quickly, if given a chance for them to be consumed by tank cleaners there will be that much less ammonia that will eventually become nitrates. Another advantage with larger pieces of LR is there is some anaerobic areas in their centers where nitrates can be processed into free nitrate and released in gas form.
Biological filters are not bad for reefs, they just process waste too fast for other natural processes to utilize them. I hope I haven't confused the issue.

 

[TimSchmidt]

So let me try to see if I understand both of you.

Vafik you're saying that the LR and LS with a clean up crew is a less efficient bio filter and maybe for a reef tank it would be better to run bio balls etc?

Skipm you're saying that the point of the LR and LS is to mimic natrual conditions and let the ecosystem consume leftover food and detritus to minimize the amount of bio load to be processed by a bio filter?

Do I have this right?

Tim

 

[Vafik]

I am mainly talking about fish waste and leftover food and detritus. If these are processed with a traditional biofilter they will be broken down into ammonia quite quickly, if given a chance for them to be consumed by tank cleaners there will be that much less ammonia that will eventually become nitrates. Another advantage with larger pieces of LR is there is some anaerobic areas in their centers where nitrates can be processed into free nitrate and released in gas form.
Biological filters are not bad for reefs, they just process waste too fast for other natural processes to utilize them. I hope I haven't confused the issue.

LoL for a min there Skipm I thought you were trying to say that a clean up crew would turn ammonia into nitrates Was hoping you didnt think that

 

[Vafik]

Ok Tim heres where I'm at. You pretty much said what I'm thinking. I good bio filter would be more beneficial for a reef. I think skipm is describing the traditional method of having a clean up crew take care of waste in a tank. You have to remember a piece of waste or left over food will go through many stomachs before it is done with. But the problem I have is if this is such a great method then why would you need so much extra equipment? Protein skimmers, phosphate reactors, chemi pure, sand filters, sumps with calpuria? When you run a tank like this you really don't have a bio filter at all.

Another advantage with larger pieces of LR is there is some anaerobic areas in their centers where nitrates can be processed into free nitrate and released in gas form.

With this little form of bio filtering no wonder its such a balancing act with SW tanks. But who knows I hear people say they have to clean there canister filters like once a week with a salt water tank. Never seen a SW tank that used a canister filter on it so I'm not sure if it would be a plus or not. I just have a feeling that a good bio filter on a reef tank would make the maintness and the balancing act alittle easier.

 

[skipm]

Using LR for your biofilter is still a biofilter, its just not as fast as using a traditional wet/dry styled filter. What I am recommending is to let nature use as much of the waste as possible BEFORE it gets cycled into nitrates which are undesireable. The less foodstuff that is processed, the less nitrates in your tank from it. Since we want to keep our nitrates as low as possible it is best to keep as many nitrates from being produced as possible. Its not really any kind of balancing act, its more like a more efficient use of available resources. Either way will work but it will be alot harder to maintain low nitrate levels when using a traditional wet.dry type filter. On the taking apart the cannister filter weekly comment the same thing applies. This is like taking sponges out of a nanocube at least weekly and rinsing them off, you do this to remove the waste built up on the sponges before it is converted to nitrates. Low nitrates is the name of the game when talking about reef filtration.

 

[Vafik]

Bam and there it is Ok so the logical thing is a planted SW tank with coral That would fix the problem. And I'm not talking about a clump of plants in a refugium I'm talking about a planted coral tank. I think it can be done. Get a long enough tank and plant the sides and leave the center for a coral rock formation. Haven't seen one of those yet I think it would look awesome.

 

[Anonymous]

What Skip said. I have done it both ways and my tank didn't turn around until I removed the two little nitrate factories - the bio wheel from my old Tidepool filter sump and the box of bio balls I had hanging on the back of the tank. Then I threw out the Tidepool and got a real sump with a refugium to add more live rock and sand. I increased my crab & snail populations and upgraded my skimmer. Once I did all of this, my nitrates plummeted and the tank began to flourish.

LR & LS (along with skimming) is what works. All you have to do is look on line at some of the nicest tanks you can find (ie tank of the Month at RC) and I believe you will see that they all use LR and/or LS in some fashion as their bio filtration. You won't find a wet/dry filter under any of them.

 

[TimSchmidt]

I do like the way this conversation is going though. It's helping me by explaining everything in detail so I can make decisions on how I'll set my tank up. In my fresh water tanks (I know apples and oranges) I rely on a natural ecosystem to help take care of my nitrites/nitrates and I don't have any problems with the levels. Thanks guys/gals!

Tim

 

[Jordan8008]

That Picture is ART WORK there Pirates Reef, what size tank is it?
:mrgreen:

 

[Anonymous]

I do like the way this conversation is going though. It's helping me by explaining everything in detail so I can make decisions on how I'll set my tank up. In my fresh water tanks (I know apples and oranges) I rely on a natural ecosystem to help take care of my nitrites/nitrates and I don't have any problems with the levels. Thanks guys/gals!

Tim

IMHO - in a nutshell - your goal should be to dispose of as much waste as you can - before the tank actually has to break it down. Skimmers help tremendously with this, but they can only remove what stays in the water column long enough to exit the tank's overflow and enter the sump and skimmer. What falls to the bottom needs to be siphoned out manually or consumed by other animals in the tank that feed off of detritus and uneaten food. Then what is left over is broken down slowly over time - naturally - by the organisms in the LR and LS.

Another reason you want to keep your nitrates low (and not use a wet/dry type of filter) is that if something happens to your tank (like a power outage) and there is no water movement and the water is no longer oxygenated - the absence of oxygen will alow the nitrates to turn into nitrites, which are extremely bad and will devastate your tank's inhabitants. The more nitrates you have in the system, the more nitrites will be created.

It was mentioned that using live rock was the "old way" of doing things. That's not true. I have been at this for 25 years now and I can tell you that the wet/dry filter systems are the old way. That's the way it was done back in the early 80's (and before that as well), until everyone came to realize just how important live rock was. Only then did it become possible to keep corals alive long term and actually have them flourish in a captive environment. Going with a wet/dry is a step back in time - not a new method at all.

I am a believer that live rock (and IMHO live sand also) is essential to a healthy reef. I would not even consider having a reef without either LR & LS. Anyway, that just my 2 cents worth.

Jordan8008 - That Picture is ART WORK there Pirates Reef, what size tank is it?

Hi Jordan, thanks for the compliment on the reef. It WAS a 75 gallon. None of that exists anymore. Lost it in Hurricane Rita.

 

[Jordan8008]

Sorry to hear that Pirates Reef, but its looks like your off to one heck of a start on your newest tank.....

thanks

Jordan

 

[Anonymous]

Sorry to hear that Pirates Reef, but its looks like your off to one heck of a start on your newest tank.....

thanks

Jordan

Thanks Jordan. I will be starting a new thread for the 140 soon. Still waiting on some equipment to come in. I am hoping that this system will be even better - and I will definitely have a sheet load of live rock in it. )

Sorry, I know this is off topic (except for the sheet load of live rock comment), just wanted to respond to Jordan... )

 

[skipm]

Thank Pirate, I didn't know about the nitrates converting back to nitrites. The power outage scenario also brings another point to ponder, with a wet/dry filter you need to have a return pump moving water acrossed the filter media in order for anything to be processed but with LR that is located in the tank some ammonia cycling is still taking place. Though not as much as normal because of the low flow without pumps and powerheads to circulare everything. With this in mind I think your bacteria bed will last longer in a LR filtered tank because depending on conditions the biomedia could dry out fairly quickly taking you bacteria as the media dries.

 

[Anonymous]

I got frustrated with the hobby somewhere in the mid 90's and sold my 200 gallon fish only tank. I had a HUGE wet dry DIY filter under it (I really wish I had pics of that monster) It contained 25 gallons of bioballs! I kept a lot of them in case I ever got back in the hobby.

Well, when I got back into it only a few years later, everything had changed. Live rock was the way to go by then, but I was old school and hadn't yet changed my way of thinking on this wet/dry filter thing.

Even though I was told it was no good, I loaded up with bio balls and even a "bio wheel!" My nitrates were outta sight! I started doing some reading and looking at pictures of tanks that I wanted to use as models and you know, the only wet/dry filters I saw were now sumps with live sand & caulerpa in them. None of the nicest reef tanks I found had one bio ball in them. Didn't take me long to realize that I was wrong and got rid of it all (well not all of them - it's hard to get rid of 25 gallons of bio balls completely

 

[skipm]

I hear what your saying and agree that its hard to change our way of thinking but I have seen so much progression in the hobby since I was hooked change seems normal to me. I too started with a home built wet/dry and NO fluorescent lighting, reefing has come a long way since the early days.......

 

[Vafik]

Some good stuff here thanks for sharing the knowledge. Just imagine all the bio balls that were made and are sitting in warehouses now useless Unless someone wants to use some for a FW tank, lol. And yes you do have a very nice Tank there Pirate.