Baffled by Nutrient Level Requirements

[Flippers4pups]

You’ll be interested in the high nutrient thread. It’s a long read but worth it.
They don’t seem to care for the most part. Amongst the heavy weight sps growers, I have never heard them mention ratios or balances.
Most organisms use nitrates more than phosphates, the availability of witch in the tank shouldn’t matter , according to them, save in extremes.
Ie , low no3 and high Po4 shouldn’t matter as the organisms still uptake the same amount as if it was high no3 and low Po4.

You may have noticed that their N03 is always greater than their P04. A particular ratio? No it's not, but they trend higher N03 than P04. Chances are if asked, they probably never encountered it the other way around. Mature systems, with loads of coral and algae grazers seem to not have pest issue. Palletta, Joshi and others have little or none snails, but do have tangs.

I have one tang in my tank and no snails. If nutrients can fuel pest algaes and feed corals, why don't I have any pest algaes in my system? Possible that corals can uptake available nutrients faster than pest algaes.

It’s an interesting question. Mine is a large, mature system. 700 plus gallons across multiple, interconnected tanks. Nutrients certainly not what I’d consider low - nitrates nominally at 20, phosphates at almost 0.2. I have absolutely no algae issues in the main 450 display, nor in the 120 refugium ..... but loads of it in the 60 frag tank. Why is that, what’s different?

Easy to start with what’s the same. Identical water chemistry obviously, and I have endeavored to match lighting as much as possible. Similar flow levels and temperatures. What’s different? Both display and refugium have most surfaces covered with corals or desirable algae’s. Frag tank has a lot of uncovered egg crate. But perhaps the biggest difference is that I have an army of herbivores in the main display and a highly motivated black tang in the refugium.

I am taking steps to moderate the nutrient levels, though with over 120 fish that’s problematic. It’s been my long held view that low nutrients is just part of preventing algae; the other is to have adequate herbivores. Also remember that absent herbivores even natural reefs can get choked with algae.

Same water, same available nutrients, totally different outcome in your system.

 

[cracker]

Thanks Reef Geezer ! My post was full of frustration . my next plan is to increase room & lighting over the refugium. I have the new sump with much larger ref & better light. but have n't installed the light yet.
So The 180 tank has very little to no Ha . Also i is nutrient deficient. However if I dose to get nutrients up, the Chaeto in the sump grows like crazy. I plan to try this with the 75 & see if I can get algae to grow in the ref/sump instead the display . So All isn't lost ! LOL

 

[saltyfilmfolks]

You may have noticed that their N03 is always greater than their P04. A particular ratio? No it's not, but they trend higher N03 than P04. Chances are if asked, they probably never encountered it the other way around. Mature systems, with loads of coral and algae grazers seem to not have pest issue. Palletta, Joshi and others have little or none snails, but do have tangs.

I have one tang in my tank and no snails. If nutrients can fuel pest algaes and feed corals, why don't I have any pest algaes in my system? Possible that corals can uptake available nutrients faster than pest algaes.



Same water, same available nutrients, totally different outcome in your system.

Uhh, I think the no3 is higher than the Po4 naturally cuz it’s constantly replenished and added by all things that rot and pee and fuel the cycle , and Po4 isn’t.

 

[Flippers4pups]

Uhh, I think the no3 is higher than the Po4 naturally cuz it’s constantly replenished and added by all things that rot and pee and fuel the cycle , and Po4 isn’t.

Agreed. With new systems there is less of build up of N03. Deficiency in N03? Possibly if corals are introduced and are showning signs of stress from lack of. Yes, other things can cause this, but unfortunately new hobbyist hit the road running with corals and then wonder why they are paling.

 

[ca1ore]

BTW I think JDA mostly nailed it. I see slower coral growth at higher nutrients. Maybe not a bad thing if your tank is well grown; though problematic if not growing turns to dying. Also instructive that I mostly keep easier SPS

 

[Graffiti Spot]

The amount of coral and the age of the tank is key imo, as well as how slow the tank was adjusted to the higher levels. A tank packed with large adjusted colonies will do better than a tank with a few corals.

 

[Flippers4pups]

Consumers are one of the key differences. Algae grows in the wild and even in tanks with low building blocks - I have .1 N and .01P and I can grow bubble and hair algae if I don't have foxface and emerald crabs. If N and P get too high, then they will inhibit photosynthesis and algae can quit growing this way.

When you see tanks with REALLY high building block levels, pay close attention... most of them did not get that way being like that and did most of their building and growing at lower levels. Not all, though. Some will tell you about species and types of coral that they have lost since letting the levels get higher... but the owners do not care and can live with the bunch that is left over. Everybody loves to talk about the Richard Ross tank, but his tank was different when it had lower building block levels... with different corals and stuff. While either can be fun and fulfilling, you cannot do the same things with higher N and P that you can do with lower... and vice versa. The slower growth can be welcome once a tank is full. The nuance matters here, so pay attention.

Generally speaking, once you have enough N and P, then you have enough... 1 N and .01P is not growth limiting and the coral can function the same as if you have 10 and .1. Even slightly elevated N and P can inhibit calcification, which is why you see some keep them low (with high throughput) to get their corals (and coralline) to grow faster. High but not too high, can brown out corals with more zoox... or sometimes make their colors deeper and darker - some love this and some hate it... to each their own. Too high can inhibit photosynthesis, which does not always kill coral, but can slow down the growth.

Low N and higher P seems to be best for corals and keeping algae at bay, but can have some cyano issues... just anecdotes, but also very common where anoxic bacteria in the rock/sand can turn most of the NO3 into N gas, but there is no direct consumer for all of the phosphate.

I seem to see much of the opposite of what your explaining with higher N03 and P04 levels limiting coral growth and health. At 20-40 ppm N03 and P04 at . 1 I'm experiencing a growth explosion with all my corals at the moment. DKH at 10.5.

October 29, 2018

Now

Sorry for the brightness of the last picture.

When water pramameters are stable for long periods of time, proper par levels, proper flow, elevated N03 and P04 and higher DKH in a mature system, with a great deal of corals can get phenomenal growth.

Can this happen over night? I would tend to agree not. Takes some time to build up the bacterial colonies to handle the elevated nutrient levels.

 

[Punchanello]

My tank is <1 year. I have had very high nitrates and phosphates and very low nitrates and phosphates, and either way I have always had some form of algae to greater or lesser degree. Manual removal by hand or helpful livestock seems to be the most useful course.

Personally I think it's a fantasy to think you won't be plagued by algae in that first year.

Algae in my tank growths thickest where organics (food and poo) settle. That's not non-organic compounds in the water fuelling algae, it's poop and food and not N and P.

 

[ReefGeezer]

Thought I might consider my newly acquired knowledge as it applies to my tank and take some steps to improve it. Any suggestions or comments would be appreciated. So here's a little history and current conditions...

I have a one-year old 90 gallon Reef. It is bare bottom and started with dry, cooked, Fiji rock. I carbon dose and have a decent and slightly over sized skimmer. I have several good sized fish in the system and feed well so nutrient input is pretty heavy. I am having difficulty maintaining any nitrate in the system and, due to limitation, phosphate has slowly risen to about .1 ppm. I have been dosing nitrate but I think it is getting used/bound by pest algae growth which increases after the dose and then slows as nitrate levels return to zero. Water chemistry parameters are otherwise fine.

The tank is in its ugly phase. I have a tan to brown, slightly fuzzy organism (algae or bacteria of some sort) that covers portions of the rocks and overflow partition and builds up quickly on the glass. It is hard to get off of the rocks and textured plastic partition. I also get some Cyano and hair algae that comes & goes. The tank has a crap load of bare rock with only light Coralline growth. There's only a couple of corals in the tank, a Monti Cap and a small unknown Acro colony. They are growing ok but color is not great.

And here's the plan. Don't be afraid to make suggestions or comments. I've got thick skin.

Initially, I'm going reduce my carbon dosing, start a GFO reactor, reduce feeding, and start doing larger, more frequent water changes with the goal of reducing the pest algae & such and balancing nutrient levels. I'll employ some elbow grease & maybe some chemical help to reduce the algae & such where necessary. I'll try to maintain nutrients at low but balanced levels. I'm also going to add some Leather Corals, more clean up crew members, and other organisms that might help the cause (Suggestions needed). Sooner rather than later I want to start adding corals to cover some of the bare real estate and proceed from there.

So far I've got the GFO reactor up & running and have built a 40 gallon, heated, ASW mixing station/reservoir and plumbed it to my sump. I hope the mixing station/reservoir will encourage me to do a better job with water changes!

 

[Graffiti Spot]

My tank is <1 year. I have had very high nitrates and phosphates and very low nitrates and phosphates, and either way I have always had some form of algae to greater or lesser degree. Manual removal by hand or helpful livestock seems to be the most useful course.

Personally I think it's a fantasy to think you won't be plagued by algae in that first year.

Algae in my tank growths thickest where organics (food and poo) settle. That's not non-organic compounds in the water fuelling algae, it's poop and food and not N and P.

Could be that this type of algae is prone to take hold in lower flow areas though?

 

[ReefGeezer]

Could be that this type of algae is prone to take hold in lower flow areas though?

It would make sense that algae/bacteria that use N&P can exist in areas of locally elevated levels where gross organics are collecting/decaying. Maybe N&P (and other ions that are less available elsewhere) are still the fuel, but are quickly used locally rather than becoming included in the water chemistry where tests can identify them.

 

[ca1ore]

I don't think it's fair to call it a myth that for sps optimal environmental conditions appear to be lower nutrients.

I don't know if its a myth or not, but that has certainly been the conventional wisdom. What I do think is true is that over time the 'rule of thumb' for ideal nutrient levels has risen, so I don't think it unreasonable to consider that low nutrient levels aren't as important as once thought.. Coral need N and P to grow, just like algae does. It may be, for example, that corals exist in the wild in low nutrient environments not because said nutrients are chemically problematic, but because they favor coral over algae. Though I'm sure studies have been done to assess the impact of higher levels of phosphate, for example, on calcification rates. In my own non-scientific way, it does appear that at higher levels my coral grow slower (not necessarily a bad thing).

 

[jda]

The ocean has very low residual values, but high throughput. Some tanks are this way as well - ZeoVit is the embodiment of this with heavy feeding and supplementation, but also heavy export with their stuff, skimmer and organic carbon. While a Zeo tank might test undetectable levels of N and P, there is a bunch run through there for the animals - BRS does a good job of describing this in their ZEO tank video if I am not making any sense.

There are references in Dr. Holmes-Farley's articles on both phosphate and nitrate that link to vast studies that show calcification decreases as either building block increases. For me, coralline slows down at 2-3 nitrate (maybe up to 5) and over .25 P. Acropora growth gets significantly faster with NSW levels of N and P... so much so that people have to limit alk to keep the calcification from forming before the coral can make new tissue (this is what the ocean does BTW).

I would like to find a way to slow down the coralline and still grow acropora fast... but they seem to go hand in hand.

It is hard to quantify "throughput" but it really should be the goal more than test kit results, IMO.

 

[Bruce Burnett]

I seem to see much of the opposite of what your explaining with higher N03 and P04 levels limiting coral growth and health. At 20-40 ppm N03 and P04 at . 1 I'm experiencing a growth explosion with all my corals at the moment. DKH at 10.5.

October 29, 2018

Now

Sorry for the brightness of the last picture.

When water pramameters are stable for long periods of time, proper par levels, proper flow, elevated N03 and P04 and higher DKH in a mature system, with a great deal of corals can get phenomenal growth.

Can this happen over night? I would tend to agree not. Takes some time to build up the bacterial colonies to handle the elevated nutrient levels.

I agree with alk just above 9 dkh I could actually see daily growth in my monti caps. After a completed cycle never had algae problems, my cleanup crew was tangs. Got rid of my skimmer and just using an ATS