Lowering Nitrates.

other porous filter media such as what?
I don't recall any porous filter media that resembles live rock... except perhaps manmade (artificial) liverock. Nothing performs denitrification like liverock except (in certain cases) a deep sand bed.

QUOTE]

Any filter media that is made to house bacteria: sponges, ceramic media, glass media, bioballs, ect

Basically this stuff:

http://www.fosterandsmithaquatics.c...cal-aquarium-filter-media/ps/c/3578/4136/4140

that's what I thought you might be referring to!

What's the insides of a plastic bioball look like? (Inside the plastic itself.) What about ceramic or glass media? Water cannot penetrate to the insides of these things!
Biomedia such as these can only support bacteria on their surface (in an aerobic zone) and thus denitrification (what happens inside liverock) cannot take place.

Anybody got a pic of a nice piece of liverock broken open?
 
Im not saying that liverock is not filled with pores for bacteria to grow, I have broken rock before. I realize bioballs are not going to cut it but the ceramic and glass media is full of pores. Have you ever looked at the inside of this media? Is this media simply not large enough therefore not able to support denitrifying bacteria? If this were the case you would link that the manufactures of these product could make it larger. I just dont see it being the case.

Any thoughts on that?
 
By the way, I am not saying any of those products reduce nitrates. In fact all of the products say that they break down ammonia and nitrite only. I am just trying to understand why. Also, why these companies wouldnt try make something that could reduce nitrates if it as simple as you saying that liverock has deeper pores. Why not make the media larger to support denitrifying bacteria? Maybe we just thought a new buisness venture :idea:
 
<<<< Nothing performs denitrification like liverock except (in certain cases) a deep sand bed.>>>>

-Gary,hi.
Depends on what you mean by deep sand bed.Personaly my thoughts are leaning more towards dsb as counterproductive.The references posted on pg.1 of this thread are why I choose about an inch of substrate and of grain size.I dont think that would be considered a dsb.I also,remain highly skeptical that liverock is superior in reduction of nitrate in comparison to sediments.1mm of a granual of sand is enough to harbor aerobic and anaerobic bacteria ,as the reference states they are found to coexist.

<<<<Take a nice solid chunk of liverock and crack it open with a hammer. The pores inside the rock (actually dead coral skeleton) is where denitrification takes place. Corallines don't inhibit the process at all IME.
>>>>

- Dreaminmel, mentioned the smell from inside live rock and IMO, it brings some interesting thoughts to discussion.I will bet if you crack open most larger sized rock your going to see signs of hydrogen sulfide (H2S)
Id bet a sp. such as brarieum could encrust the rock to the point of interfereing with the denitrifying processes leading to hydrogen sulfide production.:beer:
 
rock bottom thinking

rock bottom thinking

I've never seen anything fully encrust a rock.

1" of sandbed is very easily disturbed and much too shallow for reliable denitrification IMO.
(I'm not saying it doesn't denitrify!)

If the RC search engine will allow it (and I don't think it does quite yet) you will see that I was among the first opponents of keeping DSB's inside the display- not because they are counterproductive but rather because they allow nitrates and phosphates to remain at appreciable levels.
 
By the way, I am not saying any of those products reduce nitrates. In fact all of the products say that they break down ammonia and nitrite only. I am just trying to understand why. Also, why these companies wouldnt try make something that could reduce nitrates if it as simple as you saying that liverock has deeper pores. Why not make the media larger to support denitrifying bacteria? Maybe we just thought a new buisness venture :idea:
I've used cinder block as a substitute for liverock in the past but nothing beats real liverock IMO.
I don't see any money to be made in coming up with a liverock substitute.
Most people would prefer to enter a business venture that had a chance of turning a profit.
 
I've never seen anything fully encrust a rock.

1" of sandbed is very easily disturbed and much too shallow for reliable denitrification IMO.
(I'm not saying it doesn't denitrify!)

If the RC search engine will allow it (and I don't think it does quite yet) you will see that I was among the first opponents of keeping DSB's inside the display- not because they are counterproductive but rather because they allow nitrates and phosphates to remain at appreciable levels.

-Gary,Hi.

I would never question your experience or knowledge in reefkeeping.In fact ,I'd question my own before I'd question anyone in this forum.:)
However theres some things not quite adding up here.Kinda busy this morning,get back to this in abit.
 
I don't see any money to be made in coming up with a liverock substitute.
Most people would prefer to enter a business venture that had a chance of turning a profit.

You dont see any money to be made by comming up with a cheaper alteranative to expensive liverock? Interesting:confused:
 
Savio Spring Flo

Savio Spring Flo

That is why I asked aboput Savio Springlo Filter media I use in a Pond filter and it harbors lots of critters. It is embossed polypropylene and calcium carbonate that lasts for an entire year. This might also help with hardness in the water as well. 2 birds one stone?
 
There is no question that live rock is a wonderful denitrfier in my opinion. It's the best I've ever used. I'm in the process of adding another 150lbs for a cryptic zone( ie in a closed trash can) .

Hobby grade filter media are designed for nitrification applications in high flow ,highly oxic areas to keep them clean and perhaps more importantly where highly toxic ammonia and nitrite are effectively changed to nitrate. Without high flow they clog quickly and accumulate decaying crap ,with high flow they nitrify but don't denitrify. . Although some are porous, most have small pores for enhanced surface area and may quickly clog and are not very useful in establishing hypoxic areas well fed with C, N and P. Boballs, ceramics, etc. are great for freshwater systems but not reefs where nitrate is a major concern and nitrite is not toxic in any practical sense.

Some are using a new product , denitrifying pellets which are made of a polymer which the bacteria consume as a carbon source along with nitrate and some phosphate. The pellets which cost about $100 per liter provide surface area and a carbon source to encourage heteroptrophic bacteria to colonize them.

They are called biopellets:
http://www.reefcentral.com/forums/showthread.php?t=1694529

Seachem's matrix media claims denitrification capability. I use it. It consists of very porous( pumice stone like pebbles) but it clogs up in low flow.

Live rock is more than filter media. It contains a myriad of fuana much of which is beneficial. It is after all what reefs are made of. At this point , there is nothing quite like it,in my opinion.
 
tom...does that mean that going with a bare bottom tank is not a good idea? before i move forward with doing a 50/50 bottom (half sand, half glass) on my 120g, i'd like to know if i am inhibiting some sort of a biological function by the removal of half the sand.

:rollface:Sorry, I mised your question yesterday.

Shallow sandbeds nitirfy(breakdown ammonia and oxegenate nitrite to nitrate) as well as denitrify( take the olxygen from nitrate leving N which becomes N2, nitorgen gas). So they work quite well in my experience. Deep sand beds if staffed with benthic critters and provided with some advective flow do so as well even in the deeper areas.

Bare bottom tanks can work well if you have enough live rock and flow.

Bacteria need surface area. Sand has much more per cubic inch than live rock just because of the grain size. So when you remove sand you are removing nitrifying and denitrifying capability. Removing sand should be done in small increments to allow bacterial colonies to make up for those being removed and again adequate surface area via live rock or other forms needs to added for them to colonize.

I prefer shallow sand beds, and inch or so, for a beachy look and the extra nitrification/denitrification they afford.

If you are keeping certain anemones or fishes( wrasses, jawfish. gobies etc.) it is necessary to have some deep( 4 inches or so) areas of sand for them. This can be done by adding rock structure with pools of sand.
 
You dont see any money to be made by comming up with a cheaper alteranative to expensive liverock? Interesting:confused:
when I got into reefkeeping LR really was expensive: $9 - $13 per lb. of Marshall Island rock was common. Today's rock is a much better deal and (like Tom already posted) there's nothing that can really compare to good quality liverock.

IMO/IME good LR is one of the most important components of a successful reef aquarium.
 
I can see your point about liverock in a reef Gary. I guess us fish only guys who dont want a ton of rock in the display would like something else in the sump instead of taking up tank space in the display.

Tom, your point about low flow rates makes a lot of sense. That would show why dinitrators use bioballs and are effective at lowering nitrates and bioballs in the sump would not.
 
well i can see this topic is in good hands already kudos Tom and Gary. i have to say from experience that bioball in a sump in any # of devices and configurations is a bad idea. I think i tried them all at one point or another, if i didnt then one of my clients has, my point is they all all had the same result, lots of nitrification and little denitrification. It is my current opinion and for the forseeable future that live rock is the best and least pita solution to filteration.
 
Nitrates are not as big a concern in a fish only tank particularly if you use less intense lighting to manage nuisance algae growth. I've run fish only tanks with crushed coral and lava rock with good results. Keeping some live rock in a sump or plumbed in in a bucket or cryptic zone wouldn't hurt though.
 
i'd love to see some hard numbers or science to back up lr rock claims. so many tanks seem to be sucessful with minimal rock. i preffer the two island aquascape over the fruit stand. all i seem to find are vague 1-2 lbs per gallon guidelines. i'm a fan of lr /just don't know if it's more hype than fact.
 
The science is pretty clear. Heterotrophic denitrifying bacteria need surface area,C,Nand P and a hypoxic environment. Live rock provides a beneficial environment for them. How much is needed for a particular reef varies with bioload, nitrate import, flow and other variables such as GAC use, skimming level and on and on.
 
tom...does that mean that going with a bare bottom tank is not a good idea? before i move forward with doing a 50/50 bottom (half sand, half glass) on my 120g, i'd like to know if i am inhibiting some sort of a biological function by the removal of half the sand.



it would not matter if you had a sump with a nice deep sand bed in it and some good quality porous LR in both display and sump. you also may need to increase flow a bit, and make sure to clean detritous off of the bare bottom side of the tank that will accumulate.. as ive said before, ive seen a couple pristine, professional bare bottom tanks. so it can be done.
the lighter your rocks are (more porous), the more denitrification you are going to get. that goes into gary's comment about surface area. in more porous rock, there is more surface area inside of the rock, therefore, more filtration so to speak.
 
Gary, Tom (tmc)

Im not willing to tread to far into uncharted waters here.I think its pretty obvious (tmc)Tom has seen or has an abstract by the way hes bringing advective flow into this discussion. I have not and haven't been able to find one.Without some evidence of this though the dsb was based on anecdotal and some aquarium literature to push it along.
If there is evidence its fairly knew.

The dsb works great for Nitrate but phosphate Im unconvinced.If carbon limited they store phoshate by combining ferrous iron much like gfo does.Whitch is fine in aerobic conditions or even lower oxygen sediments.When exposed to anaerobic conditions the
reaction is reversed and allows phosphate to enter the water column.You set yourself up for this when incorporating a dsb ,IMO.
 
- tmc,Hi.

I found what you were refering to.I'm only able to read the first paragraph but it doesn't really matter at least I know now what your talking about. Someone else made a reference to RAvol.3 thought Id mention it in case some interested in this topic had it.

When I broke down my dsb I noticed how much warmer the sediment was,as Im sure your very aware of that process but wouldn't that generated heat be enough to bring any lack of carbon source to bacteria in the sediment?

FWIW-Neoz, the original poster was asking what feeding schedule and amount everyone was using.I thought Id bump up his request here as it seemed to get lost in the thread.
 
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