Help me understand nutrient control

[PDR]

I have been doing a lot of reading and research lately and have some questions regarding nutrient control. I know that nutrient levels should read above 0, and that some people actually need to dose nitrate.

Here is my situation and question.

I have a 2 year old Reefer 350 that is overstocked with fish but only has softies and anemones. I feed pretty heavy, I do not run a skimmer, but have a fuge that grows chaeto like wildfire. I do not target feed the nems or coral. I have little to no algae in the display and I do monthly water changes.

My nitrates and phosphates have read 0 for the past year or so but everything is thriving. Given the coral growth, lack of skimmer and water change schedule I obviously have plenty of nutrients in the tank so why does it always read 0? Is the chaeto that effective? or is it a combination of the chaeto and soft corals using up the n03 and po4 before it can accumulate?

Other miscellaneous questions:

1. It seems to me that just about everyone who is dosing nitrate runs a skimmer. Why not just take the skimmer offline? Am I missing something?

2. These people who end up having to dose nutrients, is this mainly just the ulns crowd or is it possible to drive nutrients too low with just a skimmer and fuge?

Thanks!

 

[NY_Caveman]

I have been doing a lot of reading and research lately and have some questions regarding nutrient control. I know that nutrient levels should read above 0, and that some people actually need to dose nitrate.

Here is my situation and question.

I have a 2 year old Reefer 350 that is overstocked with fish but only has softies and anemones. I feed pretty heavy, I do not run a skimmer, but have a fuge that grows chaeto like wildfire. I do not target feed the nems or coral. I have little to no algae in the display and I do monthly water changes.

My nitrates and phosphates have read 0 for the past year or so but everything is thriving. Given the coral growth, lack of skimmer and water change schedule I obviously have plenty of nutrients in the tank so why does it always read 0? Is the chaeto that effective? or is it a combination of the chaeto and soft corals using up the n03 and po4 before it can accumulate?

Other miscellaneous questions:

1. It seems to me that just about everyone who is dosing nitrate runs a skimmer. Why not just take the skimmer offline? Am I missing something?

2. These people who end up having to dose nutrients, is this mainly just the ulns crowd or is it possible to drive nutrients too low with just a skimmer and fuge?

Thanks!

I am not an expert, but if your tank is thriving and growing and you test low to no NO3 and PO4, then maybe you have found the sweet spot for your system. Awesome!

1. I agree with this to some degree. I also think there are other ways to add nutrients besides dosing. Dosing though is easy and measurable while feeding is a bit of guesswork. I will also say a skimmer does more than just remove NO3 and PO4 (such as gas exchange).

2. I wonder what percentage of those ULNS folks who dose also started with sterile, dry rock?

 

[sghera64]

One of the most talked about problems with ULNS pertains to SPS corals. The combination of low dissolved nutrients along with higher Alk (and intense light) contributes to rapid skeletal growth against which the coral tissue struggles to match. The result is pale SPS coral and “burnt” tips.

Keepers of these corals need to find a happy-zone of nutrients and Alk.

If you are primarily softies, or even LPS, I would suspect ULNS may only cause slower growth which you may or may not notice depending on how able your specimens are able to make use of small particulate matter and other nutrients you may not measure (Fish poop, pods, food scraps, amino acids & sugars from the chaeto).

 

[Randy Holmes-Farley Verified Community Expert]

I have been doing a lot of reading and research lately and have some questions regarding nutrient control. I know that nutrient levels should read above 0, and that some people actually need to dose nitrate.

Here is my situation and question.

I have a 2 year old Reefer 350 that is overstocked with fish but only has softies and anemones. I feed pretty heavy, I do not run a skimmer, but have a fuge that grows chaeto like wildfire. I do not target feed the nems or coral. I have little to no algae in the display and I do monthly water changes.

My nitrates and phosphates have read 0 for the past year or so but everything is thriving. Given the coral growth, lack of skimmer and water change schedule I obviously have plenty of nutrients in the tank so why does it always read 0? Is the chaeto that effective? or is it a combination of the chaeto and soft corals using up the n03 and po4 before it can accumulate?

Other miscellaneous questions:

1. It seems to me that just about everyone who is dosing nitrate runs a skimmer. Why not just take the skimmer offline? Am I missing something?

2. These people who end up having to dose nutrients, is this mainly just the ulns crowd or is it possible to drive nutrients too low with just a skimmer and fuge?

Thanks!

Skimmers do a lot of things unrelated to nutrients. Removal of organic compounds (yellowing the water, toxins, etc.), remove bacteria, aerate the water. I'd skim for the last reason alone.

Skimmers alone won't typically drive nutrients too low. It cannot remove ammonia/nitrate and phosphate themselves at all.

 

[NY_Caveman]

Skimmers do a lot of things unrelated to nutrients. Removal of organic compounds (yellowing the water, toxins, etc.), remove bacteria, aerate the water. I'd skim for the last reason alone.

Skimmers alone won't typically drive nutrients too low. It cannot remove ammonia/nitrate and phosphate themselves at all.

Right! My post above was misleading. Skimmers remove organics. Those organics have the potential to release NO3 and PO4.

 

[PatW]

This is my interpretation. You add food. The fish eat it. Fish excrete ammonia which becomes nitrites than nitrates. Fish also defecate adding nutrients to the water. I think that low levels of nutrients are constantly added to the system. It is enough for your softies and anemones. The chaeto takes up the excess nutrients preventing much algal growth and keeping levels below your detection limits.

 

[PDR]

Thanks for all the replies! I do have a couple more questions...

In a perfect world wouldn't you want to provide just enough n03 and p04 for your corals to thrive and still read 0? Is having readable levels just a way to know you are not starving your coral or is there some other reason you should have readable levels?

And with skimmers, is there anything they do (besides aerate) that chaeto (nutrient export) and carbon (toxins, water color) don't accomplish?

Thanks!

 

[PatW]

Thanks for all the replies! I do have a couple more questions...

In a perfect world wouldn't you want to provide just enough n03 and p04 for your corals to thrive and still read 0? Is having readable levels just a way to know you are not starving your coral or is there some other reason you should have readable levels?

And with skimmers, is there anything they do (besides aerate) that chaeto (nutrient export) and carbon (toxins, water color) don't accomplish?

Thanks!

The problem with a zero reading is there that there are two kinds. There is a situation where there are adequate nutrients in the system but they are rapidly being exported causing an unmeasurable reading. The other situation is that there are not enough nutrients in the system and you find out only when the corals show damage. If you have enough nutrients to show a low reading, you do know that there are nutrients present.

As for skimmers, I would think that they remove some large particulates that carbon does not remove and help with water clarity. Skimmers are efficient and convenient which is why they are almost regarded as essential in maintaining marine aquaria. A marine aquarium can be maintained quite well without a skimmer. Skimmers just make life easier. If you do not want to put a skimmer in your system then don't. It is your system.

 

[Randy Holmes-Farley Verified Community Expert]

And with skimmers, is there anything they do (besides aerate) that chaeto (nutrient export) and carbon (toxins, water color) don't accomplish?

Thanks!

Skimmers remove whole organisms such as bacteria, phytoplankton, etc. Whether that is desirable or not may depend on your perspective and whether you are carbon dosing to drive bacterial growth.

IMO, aeration alone is a big reason. Folks mistakenly think their reef tanks have high aeration, but if you have a day to night pH swing, aeration is not complete.

 

[Randy Holmes-Farley Verified Community Expert]

In a perfect world wouldn't you want to provide just enough n03 and p04 for your corals to thrive and still read 0? Is having readable levels just a way to know you are not starving your coral or is there some other reason you should have readable levels?

The problem is attaining that. in the ocean it is often attained by huge amounts of foods being consumed by corals. We generally do not properly mimic that, so try to make up for it with inorganic nutrients.