Live rock as the only denitrator?

Danielmx · 10/09/2014, 06:02 AM

Hi, I know that a well cycled live rock has some anaerobic ability which means it can help in reducing nitrates. So can I setup a system with a big sump, lets say 2-3 times the capacity of the main display tank and put a lot of live rock in it and expect that it can be enough to solve the nitrate issue in an average stocked reef tank? Thanks for any response I really need to know the answer from our experienced reef keepers.

Vapour1ze · 10/09/2014, 06:09 AM

There's really no need to do a sump 2-3 times bigger than your display, especially with bio-pellets today. You can actually get away without using as much live rock as needed before. The hobby has excelled, as well as the knowledge of many reefers... I think you need to read through some of the stickies and then post back.

There are plenty of people on here that will be more than happy to help you.

billdogg · 10/09/2014, 06:17 AM

When I had my 4' Undulated Moray who's idea of a happy meal was 2-3lbs of seafood weekly, high nitrates were just a fact of life. He was in a 150g tank by himself (he tended to eat everything else), and nitrates were consistently so far off the top of the chart as to be unreadable. I could get it down to 80-100 by doing a 75% water change, but within days they would be back. Hair Algae? You've never seen hair algae, lol

Then I finished the basement, including a fish room with room for a remote refugium. I used a 120g tank for the fuge, using a DSB (6") and copious amounts of LR (suspended off the sand but filling ~1/3 of the open space)

Within 4 - 6 weeks, with no water change at all, the nitrates had gone down to ~40, after a water change and another couple weeks, they were essentially undetectable, and remained there even with water changes only every couple months.

your mileage may vary.

Breadman03 · 10/09/2014, 06:30 AM

Quote:

Originally Posted by billdogg

When I had my 4' Undulated Moray who's idea of a happy meal was 2-3lbs of seafood weekly, high nitrates were just a fact of life. He was in a 150g tank by himself (he tended to eat everything else), and nitrates were consistently so far off the top of the chart as to be unreadable. I could get it down to 80-100 by doing a 75% water change, but within days they would be back. Hair Algae? You've never seen hair algae, lol

Then I finished the basement, including a fish room with room for a remote refugium. I used a 120g tank for the fuge, using a DSB (6") and copious amounts of LR (suspended off the sand but filling ~1/3 of the open space)

Within 4 - 6 weeks, with no water change at all, the nitrates had gone down to ~40, after a water change and another couple weeks, they were essentially undetectable, and remained there even with water changes only every couple months.

your mileage may vary.

That's what I'm looking to do with a pair of 100 gallon Rubbermaid stock tanks. Cheap, easily drilled and tough.

RocketEngineer · 10/09/2014, 06:57 AM

Research "Bucket RDSB". The original concept is from Anthony Calfo who proposed placing ~60 pounds of fine sand in a 5g bucket and flowing water over the surface. The bucket is kept closed and the flow rate is as high as the sand can take without being pushed out of the bucket. My 125g used to always test 40ppm+ nitrates. Water changes wouldn't even touch it. Three months after I brought the Bucket RDSB online and they tested 0. I was so shocked I ran the test twice.

About a third of the way down: http://reefkeeping.com/issues/2008-06/newbie/index.php

In what I've read, a 5g RDSB will work for about 100g. Calfo claims to have seen a 55g drum full of sand used on a 2000g setup. In between is kind of a grey area.

Just keep in mind that this type of filter is intended to do just one thing: reduce nitrates. There is no lighting, no critters, just sand, bacteria, and lots of flow to keep detritus from settling on the surface of the sand. I'm running 300gph on mine and that is the low end for a 5g bucket.

thegrun · 10/09/2014, 07:23 AM

As posted above, for nitrate issues a deep sand bed would be more beneficial than a sump full of live rock. There are advantages to having live rock and macro algae also in the refugium also, but simply looking at nitrates a deep sand bed would be a better option.

Danielmx · 10/09/2014, 10:12 AM

Thanks guys. I already tried dsb with lr on sumps for a long time and it did not work for me don't know why. Biopellets and other methods require equipments and maintenance that's why asked the question above because I really like the idea of lr alone handling the nitrates it's really so natural for me. Some reefers use a whole room for their filtration and equipment so my idea is not that crazy right?

Danielmx · 10/09/2014, 10:27 AM

For what I know dsb requires that you add certain sand movers like worms brittle stars and other detritivores. I live in Manila and they don't sell that here. We depend on lr alone to populate our dsbs so I think it's the reason why my dsb did not work. I followed grain size and other info that is in reef keeping guide to dsb. As for bioppellets I only used it for 3 months and never add more than the recommended amount but cyano exploded in my thank even with gfo reactor so I stopped it. Right now I'm trying vinegar dosing following the randy Holmes article. But I really want to know if a system with many lr can handle nitrates on its own.

RocketEngineer · 10/09/2014, 12:32 PM

We aren't talking about a DSB in a tank. We are talking about a remote DSB with no critters moving the sand and disturbing the bacteria. High flow across the bed prevents detritus from collecting so no detrivores. Sand, opaque container with opaque lid, and a pump. That's it. You only want bacteria so adding LR is counterproductive. Simple setup with a singular purpose.

wooden_reefer · 10/09/2014, 01:20 PM

Quote:

Originally Posted by Vapour1ze

There's really no need to do a sump 2-3 times bigger than your display, especially with bio-pellets today. You can actually get away without using as much live rock as needed before. The hobby has excelled, as well as the knowledge of many reefers... I think you need to read through some of the stickies and then post back.

There are plenty of people on here that will be more than happy to help you.

That is good to know.

I've always thought that efficient denitrification medium will come. May be it has come. I will investigate and try to obtain more up to date info on this.

cloak · 10/09/2014, 02:18 PM

Before you do anything rash, you might want to just stick with the basics first. Don't overfeed, don't overstock, do regular water changes, and try to remove as much detritus as you can with each procedure. If you can't keep nitrates under control or at a respectable level this way, then perhaps look elsewhere. JMO, GL.

d2mini · 10/09/2014, 02:48 PM

Quote:

Originally Posted by Danielmx

solve the nitrate issue in an average stocked reef tank?

There shouldn't be a nitrate issue in the average stocked tank.
Average amount of live rock, a good skimmer, CUC and good husbandry should keep nitrates under control.

Dan_P · 10/09/2014, 04:38 PM

The live rock idea might work but it may not be a result of denitrification alone.

Heterotrophic bacteria, the ones we feed vodka to, consume ammonia and can out compete the nitrifying bacteria for it. That means the ammonia goes to bacterial mass and not to making nitrates. If your system is generating a lot of ammonia, both heterotrophic and autotrophic activities can proceed in parallel, giving you both bacterial mass and nitrates, respectively. Dosing vodka would then be needed to shift the ammonia consumption over to the heterotrophs, thus dropping nitrate production.

Go with the live rocks idea but be ready with the vodka or a bucket of sand (I saw this suggestion in one of the replies. I would like to try it).

wayne in norway · 10/10/2014, 05:34 AM

Also, live rock is not a great media for denitrafication - it is very hard for water to move thro' it at any significant rate. The reason a DSB works is that water flow over the top will drive water thro' all the pore space creating a large low oxygen zone.

The limitation of DSB's compared to some other methods is they do zilch for phosphate. They are great for setups where phosphate is limited (old skool stocking, feeding every other day)

You may luck out with the live rock (luck plays a part) but be prepared to take Dan_P's advice if it doesn't work (and it usually doesn't)

10/09/2014, 06:02 AM	#1
Danielmx Registered Member Join Date: Aug 2014 Posts: 12	Live rock as the only denitrator? Hi, I know that a well cycled live rock has some anaerobic ability which means it can help in reducing nitrates. So can I setup a system with a big sump, lets say 2-3 times the capacity of the main display tank and put a lot of live rock in it and expect that it can be enough to solve the nitrate issue in an average stocked reef tank? Thanks for any response I really need to know the answer from our experienced reef keepers.

10/09/2014, 06:09 AM	#2
Vapour1ze I'm an Addict. Join Date: Mar 2008 Location: Yorkville, IL Posts: 3,036	There's really no need to do a sump 2-3 times bigger than your display, especially with bio-pellets today. You can actually get away without using as much live rock as needed before. The hobby has excelled, as well as the knowledge of many reefers... I think you need to read through some of the stickies and then post back. There are plenty of people on here that will be more than happy to help you. __________________ 93 Reef \| 220 Reef \| Basement Fish Life Support Room \| Empty Savings Account

10/09/2014, 06:17 AM	#3
billdogg Registered Member Join Date: Apr 2008 Location: Grove City, Ohio Posts: 10,806	When I had my 4' Undulated Moray who's idea of a happy meal was 2-3lbs of seafood weekly, high nitrates were just a fact of life. He was in a 150g tank by himself (he tended to eat everything else), and nitrates were consistently so far off the top of the chart as to be unreadable. I could get it down to 80-100 by doing a 75% water change, but within days they would be back. Hair Algae? You've never seen hair algae, lol Then I finished the basement, including a fish room with room for a remote refugium. I used a 120g tank for the fuge, using a DSB (6") and copious amounts of LR (suspended off the sand but filling ~1/3 of the open space) Within 4 - 6 weeks, with no water change at all, the nitrates had gone down to ~40, after a water change and another couple weeks, they were essentially undetectable, and remained there even with water changes only every couple months. your mileage may vary. __________________ I'll try to be nice if you try to be smarter! I can't help that I grow older, but you can't make me grow up! Current Tank Info: 120 mixed reef with 40b sump, RO 150 skimmer, AI Sol Blue x 2, and a 60g Frag Tank with 100g rubbermaid sump. 2 x Kessil A360w lights, BM curve 5 skimmer

10/09/2014, 06:57 AM	#5
RocketEngineer Space is big. Join Date: Feb 2007 Location: Maryland Eastern Shore Posts: 3,226	Research "Bucket RDSB". The original concept is from Anthony Calfo who proposed placing ~60 pounds of fine sand in a 5g bucket and flowing water over the surface. The bucket is kept closed and the flow rate is as high as the sand can take without being pushed out of the bucket. My 125g used to always test 40ppm+ nitrates. Water changes wouldn't even touch it. Three months after I brought the Bucket RDSB online and they tested 0. I was so shocked I ran the test twice. About a third of the way down: http://reefkeeping.com/issues/2008-06/newbie/index.php In what I've read, a 5g RDSB will work for about 100g. Calfo claims to have seen a 55g drum full of sand used on a 2000g setup. In between is kind of a grey area. Just keep in mind that this type of filter is intended to do just one thing: reduce nitrates. There is no lighting, no critters, just sand, bacteria, and lots of flow to keep detritus from settling on the surface of the sand. I'm running 300gph on mine and that is the low end for a 5g bucket. __________________ -RocketEngineer "Knowledge is what you get when you read the directions, experience is what you get when you don't." - Unknown Current Tank Info: None Currently

10/09/2014, 12:32 PM	#9
RocketEngineer Space is big. Join Date: Feb 2007 Location: Maryland Eastern Shore Posts: 3,226	We aren't talking about a DSB in a tank. We are talking about a remote DSB with no critters moving the sand and disturbing the bacteria. High flow across the bed prevents detritus from collecting so no detrivores. Sand, opaque container with opaque lid, and a pump. That's it. You only want bacteria so adding LR is counterproductive. Simple setup with a singular purpose. __________________ -RocketEngineer "Knowledge is what you get when you read the directions, experience is what you get when you don't." - Unknown Current Tank Info: None Currently

10/09/2014, 07:23 AM	#6
thegrun Registered Member Join Date: Dec 2008 Location: Garden Grove, Ca Posts: 17,023	As posted above, for nitrate issues a deep sand bed would be more beneficial than a sump full of live rock. There are advantages to having live rock and macro algae also in the refugium also, but simply looking at nitrates a deep sand bed would be a better option.

10/09/2014, 10:12 AM	#7
Danielmx Registered Member Join Date: Aug 2014 Posts: 12	Thanks guys. I already tried dsb with lr on sumps for a long time and it did not work for me don't know why. Biopellets and other methods require equipments and maintenance that's why asked the question above because I really like the idea of lr alone handling the nitrates it's really so natural for me. Some reefers use a whole room for their filtration and equipment so my idea is not that crazy right?

10/09/2014, 10:27 AM	#8
Danielmx Registered Member Join Date: Aug 2014 Posts: 12	For what I know dsb requires that you add certain sand movers like worms brittle stars and other detritivores. I live in Manila and they don't sell that here. We depend on lr alone to populate our dsbs so I think it's the reason why my dsb did not work. I followed grain size and other info that is in reef keeping guide to dsb. As for bioppellets I only used it for 3 months and never add more than the recommended amount but cyano exploded in my thank even with gfo reactor so I stopped it. Right now I'm trying vinegar dosing following the randy Holmes article. But I really want to know if a system with many lr can handle nitrates on its own.

10/09/2014, 02:18 PM	#11
cloak Moved On Join Date: Jul 2000 Location: Stockton, CA Posts: 14,854	Before you do anything rash, you might want to just stick with the basics first. Don't overfeed, don't overstock, do regular water changes, and try to remove as much detritus as you can with each procedure. If you can't keep nitrates under control or at a respectable level this way, then perhaps look elsewhere. JMO, GL.

10/09/2014, 04:38 PM	#13
Dan_P Registered Member Join Date: Aug 2014 Posts: 1,432	The live rock idea might work but it may not be a result of denitrification alone. Heterotrophic bacteria, the ones we feed vodka to, consume ammonia and can out compete the nitrifying bacteria for it. That means the ammonia goes to bacterial mass and not to making nitrates. If your system is generating a lot of ammonia, both heterotrophic and autotrophic activities can proceed in parallel, giving you both bacterial mass and nitrates, respectively. Dosing vodka would then be needed to shift the ammonia consumption over to the heterotrophs, thus dropping nitrate production. Go with the live rocks idea but be ready with the vodka or a bucket of sand (I saw this suggestion in one of the replies. I would like to try it).

10/10/2014, 05:34 AM	#14
wayne in norway Registered Member Join Date: Jul 2004 Location: Stavanger, Norway Posts: 1,271	Also, live rock is not a great media for denitrafication - it is very hard for water to move thro' it at any significant rate. The reason a DSB works is that water flow over the top will drive water thro' all the pore space creating a large low oxygen zone. The limitation of DSB's compared to some other methods is they do zilch for phosphate. They are great for setups where phosphate is limited (old skool stocking, feeding every other day) You may luck out with the live rock (luck plays a part) but be prepared to take Dan_P's advice if it doesn't work (and it usually doesn't)