Seachem Matrix + low flow through reactor = high nitrates?

[rocknut]

Was hoping to get a few opinions on this: I have another thread discussing nutrient reduction options, but wanted to ask this very specific question. I rebooted my 150 gallon reef three months ago using some really high quality Tampa Bay Saltwater live rock (150 pounds), and although my po4 have settled at 0.03 - 0.04, my NO3 numbers have stayed at 50-100. I haven't added any fish to the tank, and apart from adding small amounts of food for the cleanup crew, am not adding anything else in the way of nutrients to the tank. I have a lot of flow (3 Apex WAV pumps, plus a Tunze Wavebox, plus the return pump), and a 30 inch Venturi skimmer. I have also had 2 liters of Seachem Matrix running in my old Zeovit reactor almost since the beginning.

Is it possible that my water flow through the reactor is too slow, and this is causing my high NO3 numbers? Maybe lower flow is causing the old nitrate factory issue that used to be seen with bio balls? My flow was around 80-100 GPH through the reactor last time I checked. Hadn't thought about this until today, but figured I would try to get some opinions, because I'm pretty baffled by these high nitrate numbers.

Thanks!

 

[Joeganja]

Have you done any water changes?

 

[twilliard]

Don't let the flow get too low
This is a bio media for bacterial population growth
Also to note this media is in support of current bacterial load
I doubt the media is a cause of raising no3

Also did you cure the rock? And how much rock in total weight?

 

[rocknut]

Don't let the flow get too low
This is a bio media for bacterial population growth
Also to note this media is in support of current bacterial load
I doubt the media is a cause of raising no3

Also did you cure the rock? And how much rock in total weight?

Hello Twilliard,

Yes, this rock came from Tampa Bay Saltwater and was aquacultured in the Gulf of Mexico. This vendor collects the rock in the morning, moves it into saltwater tanks on the boat, then ships it in water to be picked up by you at the airport that night. So, there really isn't much of a curing process. There was some minimal die off the first week, but after a minor ammonia spike that first seven days, it moved through the cycle quickly, and by the second week, ammonia and nitrite had both climbed and zeroed out.

I have 150 pounds of rock in my 150 display, and as mentioned before, have what I think is a lot of random flow between the three Apex WAV pumps, the Tunze Wavebox, and the return pumps, to move the water over, under, and through the live rock.

I am probably reaching thinking that the Matrix is responsible for the NO3, but just think that the rock alone should be handling the NO3 at this point, especially since I don't have any fish yet. As I mentioned above, I have been careful to add food (1 piece of raw shrimp, cut into small pieces and hand fed to the serpent stars and rock anemones) because I don't want to stunt the nitrogen cycle by not having any nutrients available for the bacteria to process.

Anyway, appreciate your help. Thanks.

 

[rocknut]

Have you done any water changes?

Hi Joe,

Yes, I have been doing 10% water changes using 0 TDS water mixed with Reef Crystals. Also did a big 40% water change about three weeks ago. Did NO3 testing on the water change water before doing the change, and confirmed undetectable NO3. Thanks.

 

[twilliard]

What we are talking about is two different kinds of bacteria
The "benificial" bacteria that people quote serves the purpose of the nitrogen cycle resulting in no3 and that is the end of their job.
Another form of bacteria in our systems lives off of no3 but is dependant on the amount of carbon available. These are the guys that reduce no3
Your matrix is the "house" of benificial bacteria that reduce amonia to result in the end no3
So we must not get these two types of bacteria confused with eachother.

 

[rocknut]

What we are talking about is two different kinds of bacteria
The "benificial" bacteria that people quote serves the purpose of the nitrogen cycle resulting in no3 and that is the end of their job.
Another form of bacteria in our systems lives off of no3 but is dependant on the amount of carbon available. These are the guys that reduce no3
Your matrix is the "house" of benificial bacteria that reduce amonia to result in the end no3
So we must not get these two types of bacteria confused with eachother.

That is a very good point, and maybe where I am having some confusion. Are you saying (hope I get this right) that even though I have the necessary area for denrification to occur, deep inside the live rock, and inside the matrix stones, the lack of a carbon source is preventing the denitrifying bacteria from processing the NO3? Again, I feel like I am missing some very important understanding, and want to make sure I get this.

Thanks for your help!

 

[Gary Wilkinson]

Have you considered dosing bacteria and a carbon source to the system to help it mature, its something I did in the past with a new tank ?
N.B. This isn't the starter bacteria that processes the early stages of a tank cycling

 

[twilliard]

Denitrifying bacteria reduces amonia to no3
The bacteria that needs a good carbon source consumes no3
So we are talking about two different bacterium that needs two different "foods"
You have plenty of area in your tank for bacteria to populate without the use of matrix based on rock, substrate and volume.
For instance I dose vinegar to "feed" my no3 bacteria.

 

[Gary Wilkinson]

As a general rule our systems are carbon limited, VSV together or individual help nutrient export

Sugar has the highest calorific value, followed by Vodka and lastly Vinegar, there are other considerations and befits with each

Vinegar work well if using Kalkwasser for example

The Commercial Carbon sources do go beyond VSV formulations

 

[rocknut]

As a general rule our systems are carbon limited, VSV together or individual help nutrient export

Sugar has the highest calorific value, followed by Vodka and lastly Vinegar, there are other considerations and befits with each

Vinegar work well if using Kalkwasser for example

The Commercial Carbon sources do go beyond VSV formulations

Denitrifying bacteria reduces amonia to no3
The bacteria that needs a good carbon source consumes no3
So we are talking about two different bacterium that needs two different "foods"
You have plenty of area in your tank for bacteria to populate without the use of matrix based on rock, substrate and volume.
For instance I dose vinegar to "feed" my no3 bacteria.

Thanks so much, Twilliard and Gary! Feel like there was always a piece missing in the puzzle for me, and your posts have REALLY helped me out.

Would either of you recommend an additional bacteria supplement (like MB7, or Biodigest) to go along with a carbon source? I have an extra Apex DOS head that is not being used, so could set that up to dose vinegar, based on what I've read for dosing Vodka.

Thanks again.

 

[rocknut]

As a general rule our systems are carbon limited, VSV together or individual help nutrient export

Sugar has the highest calorific value, followed by Vodka and lastly Vinegar, there are other considerations and befits with each

Vinegar work well if using Kalkwasser for example

The Commercial Carbon sources do go beyond VSV formulations

I am dosing Kalk through a reactor, being fed RO/DI through my doser now, so maybe vinegar is a good way to go? Any benefit of Red Sea Nopox or something like that over simple vinegar? Less likely to get red slime?

 

[Mortie31]

Have you got enough matrix? I use 8L on my 200g and have nitrates of 1, I also use a low flow about 300l/hr, having read lots of posts on matrix and siporex low flow seems to be the key to keep oxygen levels lower

 

[Gary Wilkinson]

The Bacteria I am using at the moment is Aquaforest Pro Bio S, you would also get a good result with KZ Zeo Bak or ProBo Bio Digest, I have used both

dosing wise if not proprietary my experiance was with Vodka, I haven't used the Red Sea product so can't comment on that, I am using Aquforest NP Pro as a carbon source

What ever carbon source you decide on start below the recommended dose and build slowly 50% is a good start, the reason is the bacteria growth pulls down the ORP ( O2) the resulting bloom can create problems for the live stock
the skimmer should be set to dry skim, dat be surprised at the smell (-)
you may also find the carbonates get pulled down so watch you dKH the first week

Cyano is a different story, if you end up with very low Nitrate and residual Phosphate, these are the conditions Cyano exploits what ever the Carbon Source its to do with Cyano being able to fix Nitrogen from the water so conditions favour it over Algae

 

[Gary Wilkinson]

Have you got enough matrix? I use 8L on my 200g and have nitrates of 1, I also use a low flow about 300l/hr, having read lots of posts on matrix and siporex low flow seems to be the key to keep oxygen levels lower

actually I use a very high flow through my 15 ltrs of Siporax more than 15,000 LPH and it still works fine in the O2 rich water, I know its not what the books say, my reason was to have a very high turn over in the sump to support Ph, I found slower turnover the bacteria cultures pulled down my Ph

just a personal view (-)

I don't think you can have too much real estate for the bacteria, but it needs to be kept clear of detritus, I like Siporax but Matrix is a good media as well

 

[rocknut]

Have you got enough matrix? I use 8L on my 200g and have nitrates of 1, I also use a low flow about 300l/hr, having read lots of posts on matrix and siporex low flow seems to be the key to keep oxygen levels lower

I agree that from what I have read, more Matrix could be beneficial, but since I have 150 pounds of rock, and I am not looking to rely on the Matrix, but use it to supplement my live rock, my thought was that 2 liters should assist the overall process.

 

[rocknut]

The Bacteria I am using at the moment is Aquaforest Pro Bio S, you would also get a good result with KZ Zeo Bak or ProBo Bio Digest, I have used both

dosing wise if not proprietary my experiance was with Vodka, I haven't used the Red Sea product so can't comment on that, I am using Aquforest NP Pro as a carbon source

What ever carbon source you decide on start below the recommended dose and build slowly 50% is a good start, the reason is the bacteria growth pulls down the ORP ( O2) the resulting bloom can create problems for the live stock
the skimmer should be set to dry skim, dat be surprised at the smell (-)
you may also find the carbonates get pulled down so watch you dKH the first week

Cyano is a different story, if you end up with very low Nitrate and residual Phosphate, these are the conditions Cyano exploits what ever the Carbon Source its to do with Cyano being able to fix Nitrogen from the water so conditions favour it over Algae

Hi Gary, thanks again for your time, and advice.

I think part of the confusion for me is that it had always been my understanding that you should be able to run a reef with only live rock, skimmer, flow, and light, and this thought process that you would only need to carbon dose of you were grossly overstocked, or didn't do water changes, etc. I hadn't really considered that I could still need a carbon source at this point.
I had looked into the Aquaforest system, but was advised that my Kalk reactor would not be a good fit, so kind of abandoned that approach because: a) I just bought the reactor, and, b) really like what Kalk does for the tank. Maybe their carbon/bacteria could still work, however.

 

[twilliard]

You are in the right thought process.
However if there is no carbon source the denitrifying bacterial population will be minimal showing an increase of no3
Matrix claims to house both nitrifing and denitrifying bacteria but falls short in the explanation that denitrifying bacteria needs a carbon source to survive.

 

[Gary Wilkinson]

Hi Gary, thanks again for your time, and advice.

I think part of the confusion for me is that it had always been my understanding that you should be able to run a reef with only live rock, skimmer, flow, and light, and this thought process that you would only need to carbon dose of you were grossly overstocked, or didn't do water changes, etc. I hadn't really considered that I could still need a carbon source at this point.
I had looked into the Aquaforest system, but was advised that my Kalk reactor would not be a good fit, so kind of abandoned that approach because: a) I just bought the reactor, and, b) really like what Kalk does for the tank. Maybe their carbon/bacteria could still work, however.

No reason why the Pro Bio S and NP Pro wouldn't pull down nutrients for you

but please consider in your system

If the nutrients become UNLS there two things to watch for dKH needs to be in the range 6.5 to 8 dKH my preference is 7 > 7.5 and you must feed corals, nutrients are a quick easy meal hence the thicker skins and poorer colours, with UNLS they must be fed
there was an article a few years ago "Is Your Reef Anorexic" its quite tough provoking

 

[Fenzinna]

How long has the matrix been in your system? I run siporax, which is the same idea, although it's in my sump and not through a reactor. It's taken about 3 month's time to start showing the effects of it.

When you did your 40% water change, what was the effect on the nitrates? Did they drop and then climb again? Or did it just cut it in half?