Should I be concerned with Nitrates Levels being too low?

[drfu]

I have added a AC20 that I had laying around, ordered a In Tank media basket & 10W submersible light for it to grow some Chaeto in if for nutrient export. My trates were never that high but phosphorus has been as its only 2 months old and has quite a deep sand bed and the live rock I purchased was only partly cured.

Last week my nitrates were between 2-5, I'm thinking that good for a weeks level after a wc and lets see what happens now with the chaeto.....well a day after my weekly 15% wc my trates are now .2 (Salifert, looking from the side barely detect a color change).

Below are the rest of my parameters:
SG 1.025
Ph 8.0
Mg 1350
Phosphorus 36 ppb or .11 phosphates in ppm
Ca 531
Alk 119
My questions are as follow:
1) I know some corals like "Dirty" water, will nitrates this low cause an issue? I their any other issues with having too low of nitrates?
2) Depending on what if any levels of nitrate rise next week should I skip a water change? Maybe start going every two weeks?
3) Phosphorus levels still being high be a concern? Do i just keep on with my 15% w/c


Here is my set up below with hardware, livestock and corals. Thanks in advance for your thoughts and recommendations.

Hardware:
Aqueon 15 gallon column tank kit w/8W Power-Glo 18K T5 light fixture, 2* TrueLumen Pro 12" Marine Fusion LED's, 1 * TrueLumen Deepwater Blue 12" LED, TrueLumen 10" LED Moonlight, Fluval 105 External Canister filter (Live Rock, Filter Floss, ChemiPure Elite, Purigen, Phosgard), Fluval Surface Skimmer, Aqueon QuiteFlow 10 (Cheato) Fuge Conversion w/IM 4W SkyyeLite, Marina 100W heater.

Livestock/Invertebrates:
Hi Fin Goby mated w/ Pistol Shrimp, 2* Peppermint Shrimp, Rock Flower Anemone

Coral:
LPS Hard Corals: Frogspawn, Candy Cane, Branching Hammer, Orange Tube Coral
SPS Hard Corals: Orange Montipora Digitata, various Birdsnest, Hyacinthus Acropora, Neon Green Horn Hydnophora
Sea Fans: Corky Finger Gorgonian
Soft Corals: Devil's Hand, Colt Tree, Toadstool Mushroom Leather, White Pom Pom Xenia
Mushrooms: Hairy Green Rhodactis, Various Rhodactis, various Ricordea, Watermelon, various Mushrooms
Polyps/Zoas: GSP, Bam Bam, Devils Armour & various Zoas, Button & various polyps in various colors.

CUC:
Snails: 7 Ceriths, 5 Nassarius, 2 Bumble Bee & 4 Trochus

Décor:
15 lbs Live Rock, 10lbsCaribSea Fiji Pink Aragonite sand

 

[HighlandReefer]

IME, Xenia do better with some nitrate and phosphate. Nitrate up to 10 ppm doesn't seem to cause problems with many SPS. You probably need some phosphate as well for the Xenia.

What your trying to do is keep both SPS and soft corals happy in the same tank, so compromising will help.

Spot feeding will help and one can keep parameters lower doing this.

 

[bertoni]

I kept Xenia for years with no measurable nitrate. Carbon dosing and other approaches might be able to lower the nutrient levels enough to cause problems for Xenia, though. I think the nitrate level you mentioned is fine, although I'd work on lowering the phosphate level.

 

[drfu]

I kept Xenia for years with no measurable nitrate. Carbon dosing and other approaches might be able to lower the nutrient levels enough to cause problems for Xenia, though. I think the nitrate level you mentioned is fine, although I'd work on lowering the phosphate level.

I would rather not dose so i guess i will keep jp with weekly wc. Two things I'm looking @ for phosphorus is my ro water & the buckets/containers i keep my salt mixture.for the second maybe a good cleaning of them could help and i also have ordered my own ro/di from sprectrapure as im sure the water im getting has phosphates in it.

 

[tmz]

I kept Xenia for years with no measurable nitrate. Carbon dosing and other approaches might be able to lower the nutrient levels enough to cause problems for Xenia, though. I think the nitrate level you mentioned is fine, although I'd work on lowering the phosphate level.

That's been my experience. I keep a lot of xenia and other mixotrophic corals with relatively higher needs for organic carbon to supplement photosynthesis.
They do very well in tank that has almost no skimming and low nitrate and phosphate. They do ok in another off system tank with somewhat higher NO3 and PO4.
Even though the PO4 levels and NO3 levels in one of these tanks is similar to the main system; they don't grow at all in the main system which is dosed with vodka an vinegar and skimmed agressively. So, I suspect it's dissolved or particulate organics of acertain type or perhaps another limiting element that make the difference. BTW, all of these xenia come from a small stalk of red sea xenia gifted to me by my son about 10 years ago. I was my first coral.

 

[HighlandReefer]

FWIW, this study showed Xenia grow better with some nitrate & phosphate (N & P).


Inorganic nutrient availability affects organic matter fluxes and metabolic activity in the soft coral genus Xenia
Vanessa N. Bednarz*,
Malik S. Naumann,
Wolfgang Niggl and
Christian Wild


+
Author Affiliations
Coral Reef Ecology Group (CORE), University of Bremen and Leibniz Center for Tropical Marine Ecology (ZMT), Fahrenheitstrasse 6, 28359 Bremen, Germany
↵* Author for correspondence (vanessa.bednarz@zmt-bremen.de)
Received March 21, 2012.
Accepted July 11, 2012.

http://jeb.biologists.org/content/215/20/3672.long

From it:

"DISCUSSION

Our results of laboratory-based incubation experiments involving specimens of the common soft coral Xenia provide the first information on OM flux rates by reef-associated soft corals, one of the key benthic groups in tropical coral reef environments. In addition to presenting flux rates of soft-coral-derived OM species (POC, PN and DOC) determined under non-nutrient-enriched control conditions, we show evidence for the significant effect of mid-term exposure (4 weeks) to enriched inorganic nutrient (ammonium and phosphate) concentrations complemented by integrated measurements of key physiological parameters (Pgross, R and chl a tissue content). These physiological findings confirm the significant effect of inorganic nutrient availability on OM fluxes and key metabolic processes for the soft coral Xenia, and provide the first insights into the contribution of soft corals to OM budgets within reef environments exposed to ambient and elevated inorganic nutrient concentrations."

 

[nynick]

Might be better off trying to make the other corals happy. Xenia has grown in all my tanks, skimmed, not skimmed, refugium, no refugium. Right now with a skimmer, a refugium, an algae scrubber and low bio load...and it is still growing (a little slowly) with undetectable nutrient levels.

It is a coral you might not want to make too happy as it can over take your entire tank.

Great coral to keep as a watch dog. When they start looking unhappy, start figuring out what is wrong. They are very expressive and you can tell early on if they are not happy.

 

[bertoni]

Another point to keep in mind is that you likely won't be able to keep optimal tank conditions for every coral. It's pretty much inevitable that we need to make compromises.

 

[tmz]

Cliff, The study is intersting but I don't understand how it can be extrapolated to nitrate availability. It does focus on POC/DOC production,retetion by the xenia and potential exudation .It relies on ammonium not nitrate for nitrogen enrichment. Not sure we would see ammonium levels like those in the study in a normal reef tank. I think extra nitrogen and phosphate can increase zooxanthelae production in many mixotrophic corals as is suggested which could increase C production via photosynthetic activity and perhaps lessen their reliance on C from the water .

 

[HighlandReefer]

Yep, coral can uptake N by either using ammonia or nitrate according to studies completed.

As stated too much N & P in the water column can lead to rapid growth of the Xenia. Adding fish food, fish excretion & natural breakdown of organic matter release N & P making them available for coral growth. The trick is to not have too much P available causing problems with the SPS coral.

An interesting Israeli study released in 2012 discovered why Xenia pulse. The pulsing motion uses up food sources (energy) and has to somehow provide more nutrients (energy) than used for the pulsing motion. Xenia pulse to draw the nutrient rich water below them up to where they can utilize these nutrients.

Pulsing Xenia Mystery Solved
http://www.reef2rainforest.com/2013/05/22/pulsing-xenia-mystery-solved/

From it:

"Pulsing Generates Upward Water Flow

These measurements led to the research group’s next discovery. Analysis of the direction of water flow indicated that the motion of the polyps effectively sweeps water up and away from the coral tissues into the ambient water. Corals need carbon-dioxide during daytime and oxygen during nighttime, as well as nutrients (such as phosphate and nitrogen) during day and night. One of the challenges for coral colonies is to render their surrounding waters rich in essential commodities by efficiently mixing the water around them."

 

[drfu]

So i guess besides my phosphorus being a bit high, i am not to worry about too low of nitrates then. If a xenia doesn't make it vs the higher priced sps/lps corals I'm okay with that.

Do i keep up with weekly wc to add some trace elements back and maybe lower phosphate levels.

 

[nynick]

Your tank is fairly small so WC are a great way to keep stuff in check. I wouldn't worry too much about trace elements. Most of the stuff you need besides Ca and Alk will be found aplenty in fish poop.

I have dosed generic trace elements on and off a few times over the years and frankly I believe they are harmless but of very limited use...if of any use at all.

 

[tmz]

Yep, coral can uptake N by either using ammonia or nitrate according to studies completed.

Is there data on preference of which you are aware? Why do you think ammonium was chosen? Given the second study noted could the extra O from nitrate be an issuefor xenia?

 

[tmz]

So i guess besides my phosphorus being a bit high, i am not to worry about too low of nitrates then. If a xenia doesn't make it vs the higher priced sps/lps corals I'm okay with that.

Do i keep up with weekly wc to add some trace elements back and maybe lower phosphate levels.

I think water changes totaling 30 to 40% monthly would be adequate . Small frequent changes are preferred. The salt mix will add trace elements along with food. Not sure how much of what is in fish poo other than likely high phosphorous.

All organisms need some phosphate ,nitrogen and a source of energy usually organic carbon. They also need other minor, major and trace elements. How much of each they need and how they aquire them is not the same for every living thing or every coral.
.FWIW, ime, a range of PO4 from .02ppm to .04 ppm ,as best as I can measure it via a hanah 713 colorimeter, along with NO3 in the barely detectable range viewed from the side on a Salifert kit is adequate for a broad variety of corals including xenia. Xenia also inhabit oligotrophic(very low nutrient) waters in nature, but in those cases, I suspect nutrient flux plays a role.
0.11 ppm of PO4 is not likely to harm any corals but might be high for limiting nuisance algae .Some folks run nice sps tanks at higher levels of PO4,though. Other nutrient limitations may be in play in those tanks.
Nitrates much over 2ppm tend to negatively effect some sps , particularly seriatopora and some montipora in the context of my aquariums. I doubt keeping it higher than that is of any benefit.

 

[drfu]

I think water changes totaling 30 to 40% monthly would be adequate . Small frequent changes are preferred. The salt mix will add trace elements along with food. Not sure how much of what is in fish poo other than likely high phosphorous.

All organisms need some phosphate ,nitrogen and a source of energy usually organic carbon. They also need other minor, major and trace elements. How much of each they need and how they aquire them is not the same for every living thing or every coral.
.FWIW, ime, a range of PO4 from .02ppm to .04 ppm ,as best as I can measure it via a hanah 713 colorimeter, along with NO3 in the barely detectable range viewed from the side on a Salifert kit is adequate for a broad variety of corals including xenia. Xenia also inhabit oligotrophic(very low nutrient) waters in nature, but in those cases, I suspect nutrient flux plays a role.
0.11 ppm of PO4 is not likely to harm any corals but might be high for limiting nuisance algae .Some folks run nice sps tanks at higher levels of PO4,though. Other nutrient limitations may be in play in those tanks.
Nitrates much over 2ppm tend to negatively effect some sps , particularly seriatopora and some montipora in the context of my aquariums. I doubt keeping it higher than that is of any benefit.

I will keep up,with the water changes, with a 15 gallon column doing 2 gallons a week is simple! As for my po4, i use the ultra low phophorus so my readings are a bit different as i have to convert to phosphate.

I have a SpetraPure cpdi on order so no more ro water from my lfs with phosphates in it also should help with that.

I am also cleaning out my mix buckets, they seem a bit dirty.

No coral looks unhappy besides that my rock flower anemone decided to up and move on me to a spot i don't like but that could be a sign something is up?

 

[bertoni]

Anemones often move. It might want different lighting or perhaps it thinks it can catch more food in a different location.

 

[bertoni]

I split some posts into a separate thread since they were getting rather technical in nature.