Algae out break with 0 nitrates

[Jaxs]

Hello, I have a 135 gallon tank and recently I’ve had a bad hair algae outbreak and my nitrates have reduced to zero and phosphate have been staying steady at 0.8. I recently got a fox face to try to help with the algae but the Red Sea nutrient reduction product in case I need it. But now I’m a little confused because I’m assuming the algae is causing my nitrates to read as zero. So if I’m a test it’s zero should I even be using the Red Sea product or just maybe increase feedings. Not sure how to manage it

 

[FrugalReeferJon]

IMO, you have a nutrient imbalance with high phosphates and undetectable nitrates. Lower your phosphates by running GFO or feeding less and raise your nitrates by adding more fish or dosing nitrates. I’m not a big believer in feeding more to raise nitrates because you’re increasing phosphates also.

 

[slingfox]

You should provide more information to ic tease the chances of getting better help. Specifically, how long has the system been running, what do you feed and how often, what do you do for nutrient export, what kind of clean up crew do you have (a full census), provide full shot of tank under white light, etc.

I assume what is going on is the algae is exploding and therefor eating all your nitrates. If you can get the algae under control it is possible that nitrates will creep up.

 

[Mr. Mojo Rising]

Algae consumes nutrients very quickly, so depending how bad the algae is, it could very well show zero nutrients, but the test is skewed by the algae. Increasing feeding or trying to raise the nitrate up from zero will just result in more algae growth. IMO

 

[Gumbies R Us]

Do you have photos of the algae? We had zero nitrates in our tank, yet we had a ton of algae

 

[Dan_P]

Hello, I have a 135 gallon tank and recently I’ve had a bad hair algae outbreak and my nitrates have reduced to zero and phosphate have been staying steady at 0.8. I recently got a fox face to try to help with the algae but the Red Sea nutrient reduction product in case I need it. But now I’m a little confused because I’m assuming the algae is causing my nitrates to read as zero. So if I’m a test it’s zero should I even be using the Red Sea product or just maybe increase feedings. Not sure how to manage it

Water chemistry correlates poorly with nuisance organism growth like algae. The algae is obviously obtaining what it needs for growth.

The fact that you don’t measure nitrate in the water indicates the nitrogen cycle is now being dominated by the algae. Whatever nitrogen was once channeled to nitrate production is now going into algae biomass. This shift cannot be controlled or undone by fiddling with water chemistry parameters. The algae must be removed to change the nitrogen cycle back to producing nitrate.

Another concern is if you have coral. The algae might be depriving the coral of nitrogen. It might not, maybe they are sharing it. In either case, withholding nutrient additions or feeding less might not be good for the coral. You will need to keep an eye on their appearance and growth. And don’t let the algae shade the coral.

 

[Randy Holmes-Farley Verified Community Expert]

I agree with two important ideas above, and disagree with one.

1. It is certainly true that a lot of algae will drop nutrients as they consume it.

2. Trying to control algae by lowering nutrients is usually a poor plan since it can starve corals before solving the algae issue.

3. There's no evidence that algae is caused by some sort of imbalance in N and P. Algae thrives when there is enough N and P and many trace elements. Reducing any of those will not make it grow faster.

Algae problems are often best solved be herbivores (clean up crew). The foxface can be a good choice.

 

[CHSUB]

I agree also with Randy’s take with some important differences. I would include manual removal to CUC as the most effective method to solve algae problems.

I also don’t believe “low” nutrients are sufficient in controlling nuisance algae because of a starvation scenario. Imo, low nutrients are desirable because the organism we covet do best when nutrients are at or below the detectable threshold of hobby testing. These calcium depositing creatures operate at peak levels when nutrients are low, occupying available real estate and consuming resources. “We don’t keep nutrients low to starve the ‘bad’, we keep nutrients low to grow the ‘good”. (chsub 2026)

 

[FrugalReeferJon]

Check out this older video and take what you want from it because it’s not absolute truth for everyone. I’m not saying to follow his advice but it is something to consider.

In the past, I also had the problem of high phosphates and undetectable nitrates and GHA on my rocks, the back glass, powerheads, etc. My hypothesis for the undetectable nitrates is that my large Monti and Stylo colonies, which take up almost my entire 4 year old nano tank, as well as my other corals are taking up ammonia faster than it can be converted into nitrite and nitrate, but that’s another discussion.

When I increased my nitrates and lowered my phosphates the GHA over time lessened. It didn’t go away completely but my tank looked much better and the GHA was better manageable, whether with a cleanup crew or regular maintenance.

As he says in the video, it has something to do with the bacteria in the system being nitrate limited and not being able to process and consume phosphates. The bacteria basically stall out while phosphates accumulate.

Again, I’m not trying to stir the pot and saying everything else said in this thread is wrong. Just something to consider based on this video and my own personal experience.

 

[FrugalReeferJon]

Do you have photos of the algae? We had zero nitrates in our tank, yet we had a ton of algae

Had the same problem. Zero nitrates with GHA.

 

[Randy Holmes-Farley Verified Community Expert]

Check out this older video

I could only stand sitting through half that video because it is seriously misinterpreting the Redfield ratio to support a false theory.

The author, and many reefers, make the totally unfounded leap that the ratio that marine plankton take up (the Redfield ratio) is the ratio they want to see in the water for optimal growth. No one has ever shown that.

What happens is a totally different way to view plankton and algae growth: Liebigs Law of the Minimum.

Wikipedia has a nice discussion of it:

Liebig's law of the minimum - Wikipedia

en.wikipedia.org

In short, algae growth will always be limited by the nutrient at a concentration where it is the hardest to get in an appropriate amount. That limiting factor could be N, P, S, Se, a trace metal, etc.. If one adds more of that one single limiting growth factor, the growth rate increases until something else becomes the one limiting factor. That goes on and one as different nutrients are added in greater concentration. Eventually, other factors can become limiting, such as space to grow on, self shading from light, etc.

A flaw that many reefers think is that if N is really low, algae can use high levels of phosphate instead. THERE IS NO SUBSTITUTING different limiting factors in Liebig's law. It cannot work that way, and the analogy that these nutrients are just "food" is what sets people on the wrong path. They are organism parts, and one cannot substitute P for N in any molecule to make the same tissues.

 

[Randy Holmes-Farley Verified Community Expert]

Had the same problem. Zero nitrates with GHA.

Which is not unusual as the algae takes up nitrate, just as it would in a refugium. :)

 

[Randy Holmes-Farley Verified Community Expert]

When I increased my nitrates and lowered my phosphates the GHA over time lessened. It didn’t go away completely but my tank looked much better and the GHA was better manageable, whether with a cleanup crew or regular maintenance.

It is certainly true that organisms can become N or P limited, as I noted above. But the ratio in the water is not what limited your algae, unless one because limiting.

There can be other, more logical explanations (IMO), for your result, but one is that the phosphate that was slowly being released from the rock (also noted in the video) was gradually depleted by adding N and getting growth that consumed that P and N, and then the surface was not nearly so amenable to algae growth since it lacked its localized source of P.

I think this issue happens in many new reef tanks that use rock with phosphate bound to it.