Nitrates --Eliminating the Last 10ppm

[sen5241b]

Had my tank setup about 10 months now and my Nitrates are consistently at 10ppm although lately they jumped to 15 because I've been putting a lot of live brine shrimp in there for a new Mandarin Goby.

 

I can't get rid of the last 10 ppm!! What's the secret? As much as I appreciate the great help from this forum, I'm looking for less speculation here and more stories of things that actually worked for people to get rid of the last 10 ppm.

 

Setup:

Biocube 29G.

Upgraded stock pump to Rio 6hf (350gph), stock pump was 265gph.

Added two loc-lines one with spinning nozzle.

Koralia 1 pushing water under LR, see lower left of tank

BC29 skimmer (Uses wooden airstone, skim-mate is green tea and occasionally a little viscous crud)

2 water changes per month (there's a 20G to 25G of water in the tank so my 5g change out is over 20%)

2 handfuls of chaeto in back fuge

All water is first passed thru a piece of floss before further filtering

Passive filtering thru chemipure wrapped in floss --most water goes thru this on each pass.

Passive filtering thru a small bag of Rowaphos. --most water goes thru this on each pass.

All water also goes thru a sponge.

I blast the rock with a turkey baster on a regular basis.

Have some bioballs because they keep the tank quieter but, trust me, they're completely detritus free.

 

 

I forgot to mention I have over 30 lbs of LR in there.

[Brian Ward]

Few things:

 

1- I know you didn't ask about this, but a mandarin in a BC29 will likely starve if you don't get him on prepared foods - frozen mysis at the least. People are having much better success with ths lately, search for methods of training them on frozen food.

 

2- The problem with BioBalls is not the detritus, but rather the lack of oxygen-free space to allow aerobic bacteria to grow. The oxygen-free space forces them to process nitrates and break them apart into Nitrogen and Oxygen thus completing the nitrogen cycle. If you like having the BioBalls, be sure you rinse them in fresh water every time you change the water to remove the nitrates.

 

3- The same thing with your sponge exists as with the BioBalls. Be sure you rinse this regularly to remove nitrates.

 

4- If none of these items apply, then you simply don't have enough denitrifying bacteria available or other nutrient export mechanisms. I'm including a link to a recent ReefKeeping article on nutrient export for reference. Vodka dosing may be the most appropriate thing for you to consider. Due to the extremely small size, be sure you acquire a highly accurate device for dosing - a 1mL insulin syringe is what I recommend.

 

http://www.reefkeeping.com/issues/2008-10/newbie/index.php

[Coral Hind]

I totally agree with what Brian said, the bioballs should go. Can install a piece of plexiglass at an angle so the water can gently run down it instead of the balls?

Edited November 4, 2008 by Coral Hind

[jamesbuf]

Ditch the bioballs and replace them with these:

 

http://www.premiumaquatics.com/Merchant2/m...;Category_Code=

 

That way you'll get anaerobic respiration and get some additional denitrification. I have never used them personally, but the concept is pretty solid. I'm plan using them myself once I get the nano in my bedroom up and running.

[MisterTang]

A fast-growing "weed coral" might help. When my nutrient levels were higher, my xenia grew like mad, and now that I've gotten things stabilized, they grow much slower.

 

Also, I believe that better flow and surface area disruption is also supposed to help. I noticed a nitrate increase in my 10g when my powerhead died and I put in a smaller one.

 

Not that it's too useful, the biggest thing that helped with my last 10 ppm was working with a bigger tank. More water volume = less ppm of nitrate. As they say on WWM, "Dilution is the solution to pollution!" Since this probably isn't an option in your case, you might not get solid results unless you decrease your bio-load.

[Kevin Garrison]

Agreed on the bio balls, I finally got my sump running, it "HAD" bio balls in it. My nitrite and nitrate are screwed up at the moment thanks to that. I'm doing another water change when I get home tonight....

[Origami]

Unless you're changing out your filter pad, it can go biological on you as well to add to your nitrates.

 

The problem with bioballs and with the filter pad is they become a home to aerobic bacteria which convert ammonia to nitrite and nitrite to nitrates. Unless there's sufficient anaerobic bacteria to process the nitrates from this population of aerobic bacteria, you're going to have a build up of nitrates. So, in essence, you've got a structural imbalance in your bacterial workforce - too much environment for aerobic bacteria compared to too little for anaerobic bacteria. If you're going to bring this into balance by removing your bioballs or filter pad, you need to do it gradually over several weeks rather than all at once otherwise you may well find yourself with elevating levels of nitrate precursors - that is, ammonia and nitrite. Reducing the bioballs slowly, allows other parts of your system to grow to develop additional capacity.

 

Vodka dosing is an option but you'll have to be really careful with such a small tank. Overdosing can result in a very rapid decline in oxygen levels endangering your livestock. Vodka / sugar / vinegar added to your water column presumably works by adding a biologically available carbon source to your water column which, in turn, results in an increase in bacteria in that water column. That bacteria feed on phosphates and nitrates and are skimmed out. They also take up oxygen - hence the risk of oxygen depletion if you overdose. Consequently, you need to have a good skimmer if you're going to use Vodka or do carbon dosing. Since the bacterial metabolism involves the consumption of both phosphates and nitrates, the metabolic reaction can be limited if either drop to zero. Thus, when dosing vodka, it's possible that you can't drive nitrates to zero in a phosphate free environment. This is why, when I tried dosing carbon in my larger display, I turned off my phosban media reactor.

 

Deep sand beds and a larger macroalgae fuge or turf scrubber could also work but would probably require that you drill you biocube or siphon over the edge to a sump.

 

I would propose, however, a more conservative approach of more frequent (weekly) water changes that involve blowing off accumulating detritus from rock surfaces (usting a turkey baster) beforehand, and maybe cutting back on feeding some.

 

By the way, nitrates of 10 aren't exactly horrible. A lot of nice tanks do just fine with levels even a tad higher. To some extent, elevated nitrates can be more than compensated by elevating alkalinity. See http://www.aslo.org/lo/pdf/vol_44/issue_3/0716.pdf

Edited November 4, 2008 by Origami2547

[Rascal]

The bioballs, the sponge and filter floss are all potential nitrate factories. With regard to the sponge and filter this effect can be mitigated somewhat by frequent (daily if you are having problems) rinsing and/or changing. I am not sure this is true for the bioballs though. The problem here is that they are very efficient at breaking down ammonia and nitrite into nitrate, but the bacteria that break down nitrate need low oxygen environments like that found in deep sand beds and deep inside live rock. [Edit: looks like Origami and I were typing at about the same time -- his explanation on this is much better ]

 

Other suggestions I would normally make include increasing flow and upgrading the skimmer, maximize macro export by increasing the size and lighting of the refugium, using a remote DSB, and increasing the water changes to 1 x week. The addition of a remote DSB alone would be enough to drive down those last 10 ppm of nitrates, IMO and IME. Given your set-up, however, most of these suggestions may not be practical for you. In that case, you might want to start investigating carbon dosing. Just make sure you do plenty of homework on that before you try it. There is a good article and a couple of 40+ page threads on RC to get you started. I would definitely try the traditional methods of removing known nitrate sources and increasing water changes.

Edited November 4, 2008 by Rascal

[jason the filter freak]

Better skimmer, ditch the bio balls, ditch the sponge

[sen5241b]

I actually posted this on a couple websites and got the best answers here!

 

I only have one Mandarin goby in the tank now. I change the floss weekly except for the floss that wrapped my chemi-pure. That's been in there for a month.

 

I'll replace the bioballs with the ceramic thingys, replace the floss, up the water change outs and clean the sponge. The better skimmer, $160, is out of range right now. It seems that the more you spend on nutrient reduction the more you get into diminishing returns. In other words, eliminating the last 10ppm of nitrates is more expensive then eliminating the second to last 10ppm.

 

Also, I checked my chaeto a month or two ago and the part that got no light turned white and rotten. I got it out before nitrates got bad.

 

The flow is good enough that my featherduster hates it. He stays closed in much more since I upped the flow. It seems, however that the holes in the rocks collect detritus that the flow can't get to and so I have to turkey baste in there. The detritus collecting in the holes is allowing bryopsis to grow out of the holes -which is the main reason I posed this issue.

[L8 2 RISE]

one thing that I've been reading a lot about lately is cleaner clams http://www.saltwaterfish.com/site_11_03/pr...oot_parent_id=4

 

they're pretty cheap, and they say that one for every 5 gallons, so 6 in your case, will do the trick. I personally am not sure if they work, but I know clams are known for taking nitrates out and these, being non-photosynthetic, will do a pretty good job. Most of the discussions I've seen on cleaner clams, the user has had great success, and I personally would go for it because, what bad could it do unless they die? And that's true with most things you put in your tank. Also, a hang on refugium would be a good idea.

[zygote2k]

Why not try the natural way- Remove all resins, remove all mechanical filtration. Make a DSB in the mechanical filtration area, grow more algae in 'fuge. Do 10% water changes once a week. Cut back on feeding brine to the Mandarin or get a different fish.

[SeanCallan]

Ditch the bioballs and replace them with these:

 

http://www.premiumaquatics.com/Merchant2/m...;Category_Code=

 

That way you'll get anaerobic respiration and get some additional denitrification. I have never used them personally, but the concept is pretty solid. I'm plan using them myself once I get the nano in my bedroom up and running.

 

Have you used these? What did you think about them? I've got an old JBJ 12 laying around that might be fun to start up sometime, these would be perfect.

Edited November 4, 2008 by SeanCallan

[Highland Reefer]

Try dosing iron for your macroalgae. Many times the macro will not grow very fast because it is limited by the availability of the iron.

[Origami]

I've also got a BC29 and have live rock rubble in the first two chambers. Unfortunately, the rubble catches debris and has to be maintained (which can get a little messy). I'll be replacing at least the rubble in the second chamber with a recirculating skimmer by Sapphire Aquatics here in the next month.

 

A DSB in the second chamber is an interesting possibility but you'd have to install some kind of baffle to hold the sand back because the flow from chamber 2 to chamber three goes under the wall there. Chamber 1 is out because it takes water from high and lower in the water column. You might then put some rubble on top to keep the sand from washing out since the flow through the chambers is moderately high.

Edited November 4, 2008 by Origami2547

[sen5241b]

one thing that I've been reading a lot about lately is cleaner clams http://www.saltwaterfish.com/site_11_03/pr...oot_parent_id=4

 

they're pretty cheap, and they say that one for every 5 gallons, so 6 in your case, will do the trick. I personally am not sure if they work, but I know clams are known for taking nitrates out and these, being non-photosynthetic, will do a pretty good job. Most of the discussions I've seen on cleaner clams, the user has had great success, and I personally would go for it because, what bad could it do unless they die? And that's true with most things you put in your tank. Also, a hang on refugium would be a good idea.

 

 

Funny you bring this up but I have about 10 small clams in my tank that came in on the LR. Everyone who has the biocube is big on the idea of putting live rubble in chamber 2. I tried it and can't see any benefit. Flow that strong on LR won't allow stagnant water to build up.

[treesprite]

Set up a remote DSB. I've been considering adding a xenia refugium for a long time.

[Origami]

Everyone who has the biocube is big on the idea of putting live rubble in chamber 2. I tried it and can't see any benefit. Flow that strong on LR won't allow stagnant water to build up.

 

Live rock and live rock rubble are a key part of your biological filtration and provide an anaerobic bacterial habitat deep in their pores, not on the surface. So external flow is not relevant to the question of it's efficacy. Skimmerless nanos are a common and legitimate equipment configuration and, through water changes, can provide a perfectly suitable environment for livestock.

[sen5241b]

Live rock and live rock rubble are a key part of your biological filtration and provide an anaerobic bacterial habitat deep in their pores, not on the surface. So external flow is not relevant to the question of it's efficacy. Skimmerless nanos are a common and legitimate equipment configuration and, through water changes, can provide a perfectly suitable environment for livestock.

 

If that is the case then there is no benefit to putting LR in the back chamber.

[newfish]

Any chance that your test kit could be testing wrong?

Possibly try another test kit or take it to a LFS and have them test it for free. Most have Lab grade test kits.

 

 

Maybe even try a little bit of BioClean from Prodibio.

Edited November 5, 2008 by newfish

[Origami]

If that is the case then there is no benefit to putting LR in the back chamber.

 

I'm sorry, I don't see how I've led you to that conclusion. There is definitely value. "Skimmerless" does not mean "without adequate biological filtration." Putting live rock in the back chamber just increases the anaerobic environment for beneficial bacteria. The trade is what you use this space for. Some have used it as a refugium (scraping the black paint off the back and mounting a light there to provide the illumination needed), some have the stock bioballs there (with its attendant problems in reefs but quite viable for a FO setup), some put a skimmer in there, some put in live rock rubble ... so a host of other options exist. It's just a sump chamber - do with it what you will.

 

The upside of live rock rubble in the back chamber is an enhanced biological filter. Since most folks would probably rather not put a 6" DSB in a display this shallow, it offers an alternative to accomplish this objective. The downside that I've seen is that, without a particulate filter up front, the rubble can become a trap for detritus (the same could be said for a refugium full of chaeto). That's been my experience at least.

 

Good luck with your nitrate problem. You've got a number of options offered here that are worth considering.

Edited November 5, 2008 by Origami2547

[sen5241b]

I'm sorry, I don't see how I've led you to that conclusion. There is definitely value. "Skimmerless" does not mean "without adequate biological filtration." Putting live rock in the back chamber just increases the anaerobic environment for beneficial bacteria. The trade is what you use this space for. Some have used it as a refugium (scraping the black paint off the back and mounting a light there to provide the illumination needed), some have the stock bioballs there (with its attendant problems in reefs but quite viable for a FO setup), some put a skimmer in there, some put in live rock rubble ... so a host of other options exist. It's just a sump chamber - do with it what you will.

 

The upside of live rock rubble in the back chamber is an enhanced biological filter. Since most folks would probably rather not put a 6" DSB in a display this shallow, it offers an alternative to accomplish this objective. The downside that I've seen is that, without a particulate filter up front, the rubble can become a trap for detritus (the same could be said for a refugium full of chaeto). That's been my experience at least.

 

Good luck with your nitrate problem. You've got a number of options offered here that are worth considering.

 

 

Let me re-phrase the question: what is the benefit of putting LR in the back chamber as opposed to the front part of the tank? I can't see any.

[zygote2k]

make a simple plenum and change the area that you place rubble into a DSB. Remove the sponge and other filtering materials such as floss bags. Remove the resins. Add carbon in a mesh bag. Use R/O water and do 10% water changes once a week. Add some different types of macro to the fuge. This option will actually save you money instead of spending it. You have a small tank- keep things in perspective. Don't try dosing with vodka or using ceramic bioballs that will clog just like large sand grains. Don't do a remote DSB- try to fit it all in the area provided.

[Origami]

Let me re-phrase the question: what is the benefit of putting LR in the back chamber as opposed to the front part of the tank? I can't see any.

 

Ah, I see. I guess it's a matter of aesthetics. If you're using rubble, it may not give you the look you want in the display. The rubble that I have (which I'll be removing by the way to make room for a recirculating skimmer) is anywhere from 1/2" to 2" and irregularly shaped. It would look like trash in the display (though I've found it useful it I want a natural looking frag mount) and, because of it's size, it gives me a lot of surface area which ultimately translates to anaerobic subsurface volume.

[DDiver]

i just wanna add that i use bioballs and never had any nitrate issue..the highest its reached was 5ppm and thats when i was feeding heavily...oh and no refugium..