How Do You Maintain Nitrates Without Triggering Algae Growth?

[CHSUB]

I “target” ocean levels for No3 and Po4, (ie barely readable or 0 with hobby test kits). More than not it’s higher and I do extra maintenance, however continuie feeding fat fish and corals. I figure mother nature knows better and following her advice has worked.

 

[rishma]

I “target” ocean levels for No3 and Po4, (ie barely readable or 0 with hobby test kits). More than not it’s higher and I do extra maintenance, however continuie feeding fat fish and corals. I figure mother nature knows better and following her advice has worked.

While I believe it’s possible to have success with this strategy and I am very glad it’s working for you, many experienced reefers (including me) have had poor results while trying to maintain near ocean levels of nitrate and phosphate.

Our glass boxes are a poor approximation of the ocean. A big difference is the lack of organic N and P sources like plankton. I do not think it’s a good strategy for most reef tanks. Please understand I am not doubting your success, but I do believe the majority of reefers who attempt this will not be successful long term.

 

[CHSUB]

While I believe it’s possible to have success with this strategy and I am very glad it’s working for you, many experienced reefers (including me) have had poor results while trying to maintain near ocean levels of nitrate and phosphate.

Our glass boxes are a poor approximation of the ocean. A big difference is the lack of organic N and P sources like plankton. I do not think it’s a good strategy for most reef tanks. Please understand I am not doubting your success, but I do believe the majority of reefers who attempt this will not be successful long term.

How do you know there is a lack of organic N and P in reef tanks vs the value in the ocean? Not the actual value, but the percentage value vs the size of glass box. Imo, it is impossible for a reef tank with fed fish to lack sources of N for corals. How many leave the hobby because of algae overrunning the tank and the solution is to add inorganic fertilizers to maintain some mythical NP ratio?

 

[rishma]

How do you know there is a lack of organic N and P in reef tanks vs the value in the ocean? Not the actual value, but the percentage value vs the size of glass box. Imo, it is impossible for a reef tank with fed fish to lack sources of N for corals. How many leave the hobby because of algae overrunning the tank and the solution is to add inorganic fertilizers to maintain some mythical NP ratio?

Yikes, sorry if I touched a nerve. Again, I’m glad your approach works for you.

First and foremost, I not believe there is any merit to the idea of an NP ratio as a goal. I think that whole idea is based on misunderstanding. Unfortunately, it’s a persistent myth that resurfaces all the time. I am not sure why you went there, but I just want to get that out of the way.

I don’t really know anything. But as I understand it the ocean reefs are awash with particulate foods for corals that supply the needed nitrogen and phosphorus. I think this generally is not true in most reef tanks.

There are many examples of tanks with fed fish that have insufficient sources of nitrogen and phosphorous. This can occur for a variety of reasons but is often believed to be a cause of problems such as dinoflagellates. If you have ever battled that scourge, you get real nervous of very low nutrients.

Not long ago the general trend was for people to target ocean level nutrients.The trend has shifted away from that due to many tanks having issues. There are no absolutes, but some approaches more likely to result in success for more people.

 

[Randy Holmes-Farley Verified Community Expert]

How do you know there is a lack of organic N and P in reef tanks vs the value in the ocean? Not the actual value, but the percentage value vs the size of glass box. Imo, it is impossible for a reef tank with fed fish to lack sources of N for corals. How many leave the hobby because of algae overrunning the tank and the solution is to add inorganic fertilizers to maintain some mythical NP ratio?

Lots of reasons, including measurements (see below). You are stating an extreme position and assume we should prove it wrong, when there obviously is a simple middle ground. Of course foods supply some N and P. But asserting that truism does not provide any evidence of whether it is too little, just enough, or too much.

The idea of wanting more particulate foods is why many people dose phytoplankton and other corals foods.

Here's some data:

Aquaria subjected to active filtration via skimming present water column bacteria populations that are approximately 1/10 of those observed on natural reefs.​

Bacterial Counts in Reef Aquarium Water: Baseline Values and Modulation by Carbon Dosing, Protein Skimming, and Granular Activated Carbon Filtration

What are the bacteria populations in the water column of reef tanks, and how does that value compare with bacterial counts in authentic reef water? Does carbon dosing indeed increase water column bacteria populations (i.e., is growth carbon limited)? Does mechanical filtration (protein skimming...

reefs.com

FWIW, I do not see a lot of people leaving the hobby because they added inorganic N and P and got algae, without first stopping it and seeing if that helped. Dosing N and/or P is a fairly advanced topic, not something the local LFS pushes newbies to do. Most people with algae issues are simply not dosing N and P.

 

[MDAquatics]

Im just here for the comments. Im loving this thread, so many good comments.

 

[Desmond]

I would consider a good clean up crew including snails , fish and shrimps. Also consider lighting strenght and also natural refugiums are a nice way to keep these paramters in line. Algae is not a bad thing is controlled correctly.

 

[av8]

Its not so much about the nitrate level, its more about the doc's.

This is an amazing article if you have the time to read it.

DOC is The Most Important Parameter For A Healthy Reef Tank: Here’s a New Method to Manage It | Reef Builders | The Reef and Saltwater Aquarium Blog

In this article, I will provide an overview of my take on the current zeitgeist of reefing and explain why the entire industry is ignoring a critical aspect of coral care. I will explain what issues…

reefbuilders.com

I've read the article a couple of times ... yet I'm left with no plan pf action .

 

[CHSUB]

Lots of reasons, including measurements (see below). You are stating an extreme position and assume we should prove it wrong, when there obviously is a simple middle ground. Of course foods supply some N and P. But asserting that truism does not provide any evidence of whether it is too little, just enough, or too much.

The idea of wanting more particulate foods is why many people dose phytoplankton and other corals foods.

Here's some data:

Aquaria subjected to active filtration via skimming present water column bacteria populations that are approximately 1/10 of those observed on natural reefs.​

Bacterial Counts in Reef Aquarium Water: Baseline Values and Modulation by Carbon Dosing, Protein Skimming, and Granular Activated Carbon Filtration

What are the bacteria populations in the water column of reef tanks, and how does that value compare with bacterial counts in authentic reef water? Does carbon dosing indeed increase water column bacteria populations (i.e., is growth carbon limited)? Does mechanical filtration (protein skimming...

reefs.com

FWIW, I do not see a lot of people leaving the hobby because they added inorganic N and P and got algae, without first stopping it and seeing if that helped. Dosing N and/or P is a fairly advanced topic, not something the local LFS pushes newbies to do. Most people with algae issues are simply not dosing N and P.

Lots to think about in terms of organic nutrients. I started directly feeding my corals and noticed a difference in growth and health. When in the past I believed corals could do fine only relying on zooxanthellae. Imo, while the net availability of organic food in the ocean is greater, that doesn’t mean the corals can’t receive the optimum amount of organic nutrients in the reef tank. Imo, if corals look pale or malnourished they should be feed directly. Unhealthy pale corals and uncontrollable nuisance algae are two completely different problems and, imo, both can’t be fixed by dosing N and/or P.

Ime, nuisance algae is the single biggest threat to the hobbyists. Having the ability to control it is critical for success. Regardless of the type of algae, I don’t believe raising inorganic nutrients in a reef tank will make it easier to control.

 

[CHSUB]

Yikes, sorry if I touched a nerve. Again, I’m glad your approach works for you.

First and foremost, I not believe there is any merit to the idea of an NP ratio as a goal. I think that whole idea is based on misunderstanding. Unfortunately, it’s a persistent myth that resurfaces all the time. I am not sure why you went there, but I just want to get that out of the way.

I don’t really know anything. But as I understand it the ocean reefs are awash with particulate foods for corals that supply the needed nitrogen and phosphorus. I think this generally is not true in most reef tanks.

There are many examples of tanks with fed fish that have insufficient sources of nitrogen and phosphorous. This can occur for a variety of reasons but is often believed to be a cause of problems such as dinoflagellates. If you have ever battled that scourge, you get real nervous of very low nutrients.

Not long ago the general trend was for people to target ocean level nutrients.The trend has shifted away from that due to many tanks having issues. There are no absolutes, but some approaches more likely to result in success for more people.

Not sure what you mean by “touched on nerve”, since having discussions here is generally better than watching tv, and I can only play pickleball 3 or 4 hours a day?

Before the “trend” there was years of success with lower nutrients and like most trends, they disappear. I’m not aware of any dinoflagellate that can survive with insufficient sources of N and P. Zooxanthellae is a dinoflagellate, why can’t it continue feeding the host corals when inorganic N and P are limited?

 

[av8]

I feel nitrates and phosphates are only a slice of the pie, and get too much focus.

I have zero herbivorous fish. I have a small cleanup crew for a 75g tank. And I don’t believe they contribute much at all.

My display has no algae issues. But I do have one rock in a rear corner that has hair algae. It never gets better or worse. Just seems to want to grow a certain amount then stops. I’ve plucked and it grows back. I’ve plucked and put snails and hermits directly on the rock. They just leave. It comes back. Then it stays a certain way.

I’ve run my tank at .04 phosphates and 5 nitrates for 1.5 years. I hit .98 phosphate in a spike for a few days. I currently run the tank at .4 phosphate and 10-20 nitrates. Regardless of any of these numbers the outcome is the same. Zero display algae except for the one rock

do you see tons of critters cleaning my sand and glass? I have 10-15 snails tops, probably 5 hermits. In a 75 gallon tank

Not saying that they don’t work for most people, but there is more at play here because I run higher nutrients, have a tiny clean up crew, and my tank does very well. Film algae on glass is all I regularly get

If it matters, I do have a large yellow sponge colony in the display (pic 3) and I do have a cryptic zone in my sump with a few species of sponge as well

While your deep sand bed may not be a full on Jober (with pelnum/anerobic zone,). I cannot tell from the pictures, I'd like to know how you are keeping your N & P from being zero?

 

[VintageReefer]

What algae are you harvesting?

I don’t have an exact id here. Scrubbers grow algae based on the spores in your tank. You can’t take algae from one scrubber and seed another. It almost never works.

And with this scrubber on my nano, I tried to bypass the break in cycle by taking healthy turf algae from my 75g tank scrubber, and put it in the 15g nano scrubber. Twice. It all died in a few days. Cleaned the scrubber and it grew its own strain

 

[VintageReefer]

While your deep sand bed may not be a full on Jober (with pelnum/anerobic zone,). I cannot tell from the pictures, I'd like to know how you are keeping your N & P from being zero?

Sandbed started off as 3” across
After 10 years, the stronger mp40 on the right has pulled some sand rightward and made a slope, so I do taper from 3inches up to 4” on the very right. Viewing from
The side that 4” corner tapers up to a 5” sand bed in my back right corner

The rest everywhere is 3” except for a dip in the back from a fish that dug out a cave

How do I keep from hitting 0 nitrates and phosphates ? I have. Many times. Never an issue

I currently am at .45 phosphate and about 13 nitrates.

I feed heavy and I target feed all my corals individually. My scrubber is my only equipment for nutrient control, I imagine my live rock, sand, and cryptic zone sponge all are biologically assisting in various ways. I don’t waterchange or run a skimmer. The scrubber is all I use.

I can increase hours or decrease hours on the scrubber leds to influence my numbers, same for display tank.

 

[VintageReefer]

Pick any date where my numbers are whatever value stands out, and I can show you my tank at that time if your curious to see low vs high levels in the same tank / corals