the secret to colorful,healthy corals....obvious to some,elusive to many

[karimwassef]

Hmmm... I may get flamed but I need to clarify something, if only to make sure my understanding aligns with what others experience ...

1. Natural reefs have high food content (organics) and low nutrient levels (inorganic).
2. To emulate this, I feed a lot, but then must also apply aggressive export mechanisms to remove excess organics and as much of the inorganic nutrients as possible (which I do).
3. Very low nutrient systems don't feed enough, so while they achieve low nutrients, they also starve their reef.
4. If it's possible to have a constant food supply while maintaining zero nutrients, that would be best for coral health and growth.

Some of the above may be repetitive but I want to be clear from different perspectives here.

The question: based on the above, why do some still believe that there is a threshold of nutrients (P, N) that must be maintained for color, growth and health? Isn't that contrary to the points above?

Is it just that small reefs cannot exercise sufficient export to really remove all nutrients, so the threshold is really a measure of food availability by proxy?

Just want to be clear...

 

[Nano sapiens]

1. Natural reefs have high food content (organics) and low nutrient levels (inorganic).
2. To emulate this, I feed a lot, but then must also apply aggressive export mechanisms to remove excess organics and as much of the inorganic nutrients as possible (which I do).
3. Very low nutrient systems don't feed enough, so while they achieve low nutrients, they also starve their reef.
4. If it's possible to have a constant food supply while maintaining zero nutrients, that would be best for coral health and growth.

Some of the above may be repetitive but I want to be clear from different perspectives here.

The question: based on the above, why do some still believe that there is a threshold of nutrients (P, N) that must be maintained for color, growth and health? Isn't that contrary to the points above?

Is it just that small reefs cannot exercise sufficient export to really remove all nutrients, so the threshold is really a measure of food availability by proxy?

Corals are mixotrophic, so they can utilize many different nutrition sources including both organic and inorganic nutrients. Those that keep their tanks with somewhat higher than NSW levels of PO4 and NO3 are providing more abundant inorganic resources than the organisms would typically encounter on an oceanic reef. This is often done due to the realization that providing as much organic nutrition as encountered on a natural reef in a reef aquarium, while still retaining the very low inorganic levels found on the reef, is very difficult.

As far as small 'nano' reefs are concerned, nutrient export is not so difficult (in some ways easier since the smaller live rock pieces can be moved more easily to facilitate detritus removal). However, the smaller water volume in relation to the biomass means that the water can acquire elevated levels of some substances more quickly than a larger system (and conversely, can also see faster bioassimilation of some elements that can then become depleted). Hence the recommendation for more frequent water changes than typically suggested for a large system to keep element levels in relative balance. One can feed such a small system a surprising amount of food and still maintain low NO3 and PO4 levels, but only when maintenance techniques are effective and performed consistently.

 

[CStrickland]

Is it just that small reefs cannot exercise sufficient export to really remove all nutrients, so the threshold is really a measure of food availability by proxy?

That's pretty much how I take it, well put.
Like, people have noticed that .02 ppm nitrates and .003ppm phos are where they see the happiest tank because the systems that result in those numbers are the ones that have achieved the right balance of import of food to export of food and nutrients. Underfed bb's, tanks that add too much food, tanks that don't remove enough food or enough nutrients, each can be out of balance and wind up with numbers that aren't in the preferred range. But what we observe is not the issue itself, so you can get in trouble chasing those numbers.

The trick is what the test numbers mean, so you can fix it. I think proxy is a good way to think about it. As in, if your tank is dirty and you underfeed you don't have a "nitrate problem." Rather, you have an export problem with a nitrate symptom.

PS I read "small reefs" to mean our tanks, like smaller than the ocean

 

[karimwassef]

That's pretty much how I take it, well put.
Like, people have noticed that .02 ppm nitrates and .003ppm phos are where they see the happiest tank because the systems that result in those numbers are the ones that have achieved the right balance of import of food to export of food and nutrients. Underfed bb's, tanks that add too much food, tanks that don't remove enough food or enough nutrients, each can be out of balance and wind up with numbers that aren't in the preferred range. But what we observe is not the issue itself, so you can get in trouble chasing those numbers.

The trick is what the test numbers mean, so you can fix it. I think proxy is a good way to think about it. As in, if your tank is dirty and you underfeed you don't have a "nitrate problem." Rather, you have an export problem with a nitrate symptom.

PS I read "small reefs" to mean our tanks, like smaller than the ocean

Thanks. Yes I meant small as in our home aquariums compared to the ocean or systems that have access to a flow of NSW. Maybe I should have called them "captive reefs"

 

[karimwassef]

Corals are mixotrophic, so they can utilize many different nutrition sources including both organic and inorganic nutrients. Those that keep their tanks with somewhat higher than NSW levels of PO4 and NO3 are providing more abundant inorganic resources than the organisms would typically encounter on an oceanic reef. This is often done due to the realization that providing as much organic nutrition as encountered on a natural reef in a reef aquarium, while still retaining the very low inorganic levels found on the reef, is very difficult.

As far as small 'nano' reefs are concerned, nutrient export is not so difficult (in some ways easier since the smaller live rock pieces can be moved more easily to facilitate detritus removal). However, the smaller water volume in relation to the biomass means that the water can acquire elevated levels of some substances more quickly than a larger system (and conversely, can also see faster bioassimilation of some elements that can then become depleted). Hence the recommendation for more frequent water changes than typically suggested for a large system to keep element levels in relative balance. One can feed such a small system a surprising amount of food and still maintain low NO3 and PO4 levels, but only when maintenance techniques are effective and performed consistently.

Hmmm... Ok. So that line of thinking says that inorganic nutrients are good and necessary. That contradicts what I was thinking. I realize that corals farm symbiotic zooxanthelle in their tissue to convert light into usable carbohydrates and in the process, they need access to C, N and P, but I thought the levels necessary here were very very low?

 

[Big E]

It's not always in the numbers...........yes. it's good to be in a range, but it's no where near as narrow as some state. This range varies from tank to tank.

This range also applies the Cal & alk levels. You have to know your own system.

I'll give a very simple example that usually clears up some of this----

A 100g tank with .03 PO4 and .2 NO3 with two fish has pale corals......that same 100g system with those same exact readings and ten fish has thriving colors and growth.

Another comment................most people do it backwards. They force the system into that tight number target and can't understand why their acros aren't thriving. This is usually accomplished with all kinds of additives, chemicals, ect. This type of reefing becomes a dogmatic goal and tunnel vision usually ending up in a mess.

It's much easier to get in a wider range and let things settle......this takes patience and observation along with testing. When everything is thriving is when you take your more rigid numbers to target and keep for the future........those will be more written in stone for your set up.

 

[markalot]

I love this thread, every few months more great discussion.

My current observations with nutrients seems to confirm that every tank is different.

In my smaller tank, was a 29 now 40, I had very pale corals so I started dosing nitrate without changing anything else (my nitrate was 0) and the coral colors exploded and now I have better colors on acros in there, under LED, than I do in my 150 under T5's. I've tried to mimic the same numbers for PO4 and NO3 in my larger tank and the results are not the same. :rollface:

I'm missing something, mis-measuring something, or something else ...

 

[Yarm79]

What are you using to add the nitrate?

 

[00101]

I'm sorry if its been asked before, but I haven't read through the thread in a while, but with elevated inorganics, how is algae kept under control? Large CUC and frequent cleaning?

 

[mathman7728]

yeah, how do you dose nitrates?

 

[malira]

yeah, how do you dose nitrates?

A lot of us use spectracide stump remover.

2 tbs desolved into 12 Oz of rodi water.
10 ml brings 80 gallons up 1.5 ppm.

There are great threads on *********.
The other big reef keeping site. Reaftooreaf.

 

[AugustWest]

Any info on the amount of sodium nitrate ( food grade from Amazon.com) to use in place of the potassium nitrate?

 

[00101]

Any info on the amount of sodium nitrate ( food grade from Amazon.com) to use in place of the potassium nitrate?

Almost exactly the same. Which way are you measuring? Grams per liter? Its going to take a touch of math, but anyway NaNO3 is 85g/mol and KNO3 is 101g/mol give or take. So for every 101g of KNO3 you were using you only need 85g of NaNO3. So say you were using 50 grams of KNO3 in some amount of water, you would use about 42.5g NaNO3 in the same amount of water.

 

[sensei]

I am interested to know if any of you having an sps dominated tank run algae scrubber?

I ask because some time ago most of my sps frags lost their color a few weeks after being in my tank. my parameters were: KH = 7.45, Mag 1300, Cal 440, NO3=2,PO4 =0 (hanna). Then, I removed GFO and PO4 climbed to 0.06 and during this time sps started gaining color, I could see improvements in color every two days but after a couple of days PO4 climbed to 0.12- 0.14 so I thought if would be a good idea to add an algae scrubber to control PO4 naturally with scrubber because filtration is done by algae rather than mechanical media.
After installing algae scrubber PO4 measured cero when I tested 10 days after scrubber started. now it has been 20 days of having the algae scrubber in the tank with PO4 =0 (hanna) and I believe some of the sps have lost some color. I have made no other changes.
please let me know your experiences.
thanks

 

[markalot]

I don't run a scrubber but the answer seems obvious. No matter how you remove it very low PO4 is not good. Can you adjust the scrubber so you achieve some kind of elevated PO4 reading?

 

[herring_fish]

You should be able to dial in a reading that you are looking for by adjusting the photo period. Just back off on the time that the lights are on until you get what you want. The balance between N and P might be harder to achieve by adjusting the photo period so you might have to choose which one is more important and use that as the guide.

Sometimes, the amount of live rock and other factors can affect the amount of bacteria that you have in your tank. Bacteria in the tank can also contribute to the reduction of the nutrient load in the tank but it removes N and P in a different ratio than algae does so your result may vary from the next user.

On a side note, if you look at the posts of some people that dose vodka, you will find that some of them carefully dose Nitrates for example so that bacteria in those tanks are not limited which can cause the bacteria's effectiveness to be depressed. I played with vodka to grow bacteria as a food source, not to export waste. After dosing vodka, I found that my ATS starved for N and stopped working. After dosing Nitrates, my system came back into balance and the scrubber began to work again.

Some people dose waste products to do very fine tuning of both N and P to keep them on their perfect range but in most cases, that is not necessary and just too much of a hassle to mess with and can even be dangerous.

Hopefully, backing off on the photo period will be all that you would need to do.

 

[sensei]

I don't run a scrubber but the answer seems obvious. No matter how you remove it very low PO4 is not good. Can you adjust the scrubber so you achieve some kind of elevated PO4 reading?

Markalot

Thanks for your answer.
I am trying to find out if there is a way to fine tune the algae scrubber to have measurable levels of PO4
in your experience what levels of PO4 and NO3 do you find for your sps to do better?

thanks again

 

[sensei]

You should be able to dial in a reading that you are looking for by adjusting the photo period. Just back off on the time that the lights are on until you get what you want. The balance between N and P might be harder to achieve by adjusting the photo period so you might have to choose which one is more important and use that as the guide.

Sometimes, the amount of live rock and other factors can affect the amount of bacteria that you have in your tank. Bacteria in the tank can also contribute to the reduction of the nutrient load in the tank but it removes N and P in a different ratio than algae does so your result may vary from the next user.

On a side note, if you look at the posts of some people that dose vodka, you will find that some of them carefully dose Nitrates for example so that bacteria in those tanks are not limited which can cause the bacteria's effectiveness to be depressed. I played with vodka to grow bacteria as a food source, not to export waste. After dosing vodka, I found that my ATS starved for N and stopped working. After dosing Nitrates, my system came back into balance and the scrubber began to work again.

Some people dose waste products to do very fine tuning of both N and P to keep them on their perfect range but in most cases, that is not necessary and just too much of a hassle to mess with and can even be dangerous.

Hopefully, backing off on the photo period will be all that you would need to do.

Thanks for the answer. I was posting the previous message when you answered.
I dose NOPOX ( which includes alcohol, sugar and acetic acid) and still do after adding the algae scrubber, but I only dose 15ml per day. My NO3 is 7.5 ppm and I have not seen a change jet with the addition of the algae scrubber, but my PO4 did drop fomo 0.12 to 0 in less than 10 days
I was running my ATS for 16 hours and it sounds logical to reduce the photo period to lower the filtration of the scrubber, but now I have cero.
should I turn off lights until PO4 show again and then turn on lights slowly after that? maybe start with only 8 hours? please tell me what do you think

what level of PO4 and NO3 do you have with the algae scrubber running?
do you have a DIY scrubber or do you use one fomo turbo aquatics or any other?

thanks for your answer

 

[herring_fish]

I have run an ATS since the early 90's. The ATO crashed my tank while I was on vacation so I am starting a new 180 gallon tank. I designed and built a true dump bucket style Algae Turf Scrubber. They all work about the same, having different positives and negatives but they all simply grow algae.

Most of the time, I ran N=0 and P=0. Only recently have any guide lines been establish/suggested. I am not an expert on the "œperfect range" for either N or P. If you spend some time searching, you can find what people think are the right amounts to have.

After having my melt down, I plan to buy a control system so I will have the ability to fine tune my light period to better regulate pH and the dosing of all kinds of things, Auto Top Off, foods, nutrients, etc.

I'm just about finish with the cabinet build and will soon be putting water in the tank. At that point I will be revisiting the threads. Unfortunately, I don't remember the names of the threads so I will have to re-research the ones that espouse the "œperfect" levels of just about everything. Of course they do not all agree so there isn't just one place to look.

 

[sensei]

I have run an ATS since the early 90's. The ATO crashed my tank while I was on vacation so I am starting a new 180 gallon tank. I designed and built a true dump bucket style Algae Turf Scrubber. They all work about the same, having different positives and negatives but they all simply grow algae.

Most of the time, I ran N=0 and P=0. Only recently have any guide lines been establish/suggested. I am not an expert on the "œperfect range" for either N or P. If you spend some time searching, you can find what people think are the right amounts to have.

After having my melt down, I plan to buy a control system so I will have the ability to fine tune my light period to better regulate pH and the dosing of all kinds of things, Auto Top Off, foods, nutrients, etc.

I'm just about finish with the cabinet build and will soon be putting water in the tank. At that point I will be revisiting the threads. Unfortunately, I don't remember the names of the threads so I will have to re-research the ones that espouse the "œperfect" levels of just about everything. Of course they do not all agree so there isn't just one place to look.

I look forward to seing your new tank,
thanks