Does live rock remove nitrates?

[Reefer Rob]

I've always thought that algae plays a more important roll in denitrification than it's given credit for. When I switched from PCs to T5s my nitrates went from 20 to 10, and when I took a DSB refugium with too low of a flow off line it went to near 0. I'm thinking the biomass of algae living inside live rock and sand would be equal to or greater that that of bacteria. Perhaps buying or making rock with an open porous structure is more important for the growth of algae rather than bacteria, allowing light to get farther into the rock.


For anyone considering carbon dosing to increase bacteria efficiency, sugar will work as well as any of the commercial probiotic systems, but the down side is it doesn't come with an instruction manual. If you're not willing to spend a couple of weeks researching it before you give it a try, it's far safer to stick with Zeovit, Polyp Lab etc. which has a dosing regimen already established for you.

[kwirky]

sorry for the long read!

I read a non-reef oriented scientific paper once on denitrification and how they perform it in water treatment plants. It's very difficult because there are about 100 strains of bacteria that nitrify and denitrify. Some bacteria convert nitrates back to nitrites, some to nitrogen. The study found that finding the "right" bacteria was difficult and they managed to cultivate the "right" bacteria through collecting soil samples from around the world. (On a side note, that article was talking mainly about an interesting study of using organic cotton as a carbon source for denitrifying bacteria instead of traditional sulphur; they were early yet surprisingly positive results)

Now to our aquariums. Natural "filtration" methods are extremely complex. There was an advanced aquarist article on natural deep sand beds where they tested them with livestock and without. The tests with livestock were VERY unpredictable. I think that can correlate to everyone's experiences with denitrification in their tanks. Some people say it happens, some it doesn't, probably because of the great variance in our liverock and the animals (including microscopic) we have in our systems.

Now going to bacterial products like reef-fresh and zeovit:

Originally Posted by Delphinus

I'll say one thing about carbon dosing though, 3 weeks of "Polyp Laps Reef-resh" has done what a year of running sulfur could not, and for the first time in well over a year I have sub-10 nitrate readings in my ritteri tank. Wish I knew what the difference was with this tank and its resistance/resilience to denitrification... it's really weird.

I've noticed some interesting results very quickly with zeovit too. 2 days ago my tank was at 5ppm nitrate (salifert kit). I did a 10% water change that day. Tested today (2 days later) and it's at 2.5ppm. I know those are VERY short term results but it makes me VERY excited about the potential of the system.

I think that these bacterial products are doing a good job at taking the organic compounds (phosphate, ammonia, nitrate, nitrite, nitrate, etc etc) and converting them into less/non toxic chemicals that can be removed by the protein skimmer. And then there's zeovit where the mixture of zeolytes is doing something confusing in the mix too. Zeolytes are mostly carbon based which could possibly explain the efficiency of zeovit's bacteria. Zeolytes are being studied right now along with graphite for carbon-based nano-technology.

The results of bacteria products I think are more interesting to me than natrual nitrification/denitrification because of the results I've seen with my own eyes in tanks running a biological supplementation product. I think the real mystery of these bacterial products is that they're proprietary products that we can't really replicate on our own. These companies have already performed a lot of research and figured things out that work. It makes me wonder if any hobbyists will eventually figure out what's "in" zeovit and reef-fresh and the rest.

[StirCrazy]

Oh the fun ones I miss when I am gone.

OF course liver rock removed nitrate, well that is if it is in good condition and the right type. it has to have enough porosity and they type of fissures that can create anoxic areas.

I know when I bought my tank I took 240lbs of established liver rock and put it into a cycling tank with 30ppm nitrates. in 24 hours my nitrates were never seen again.

now what makes bad rock or reduces the amount of nitrate reduction. Coraline algae. the more this covers the more it seals. That is why I think people who do racks for there rock to get by with less rock are just asking for trouble down the road. I personally thing you need to have a substantial amount of rock that doesn't get light that way Coraline can't seal it up.

when I had the stuck heater incident, I had a lot of coral dying in my tank in efforts to save them (was a heavily stocked coral tank and everything died overnight) and still not one nitrate measured as I had enough rock to handle the on slot of ammonia, nitrite, nitrate.

Steve