Nitrate, phosphate and algae.

[kilnakorr]

Hi

Brand new to the saltwater arena.
Comming from heavy planted freshwater aquariums, I can't help wonder why I keep read and hear that nitrate and especially phosphates causes algae.
Are there any scientific papers on this?

The same thing was considered a rule in freshwater for many years, but now proven not to be true. In fact, in planted tanks the opposite is true. Lack of these causes algae.

Basically, to much decaying organic matter is the reason for algae outbreaks, and elevated nitrates/phosphates are result of this.

Soooo, anyone done tests or have experiences with algae and phosphates levels?

 

[beaslbob]

In marine systems macro algae, turf algae, and to a lessor extent turtle and other marine plants serve the same purpose and for exactly the same reasons as plants in fw planted tanks

 

[kilnakorr]

In marine systems macro algae, turf algae, and to a lessor extent turtle and other marine plants serve the same purpose and for exactly the same reasons as plants in fw planted tanks

Not sure what you're trying to say. In marine tanks we use various algae to remove phosphates. In planted tanks (heavy planted, high light etc.) we DOSE a lot of phosphates.

I know corals aren't a fan of high phosphate levels, but is it just a 'myth' that high phosphates causes algae in marine tanks?

 

[Jgg12002]

As far as I know you need nitrates and phosphates For a healthy ecosystem. No different then a planted tank. I was keeping my planted tank to clean and all of the plants died. After raising my nitrates and phosphates from undetectable my corals have better growth and color In my reef tank
just my 2c
John

 

[beaslbob]

The dosing phosphates in fw planted is to feed the plants. With no dosing you can add more fish or the plants just grow slower.
In either the idea is to balance out and stabilize the system with plant life.

 

[kilnakorr]

The dosing phosphates in fw planted is to feed the plants. With no dosing you can add more fish or the plants just grow slower.
In either the idea is to balance out and stabilize the system with plant life.

Well, I'm trying to understand why so many people in the saltwater world, youtube, forums etc., are saying "high phosphates causes algae". Wondering, if this is just something that has always been a 'rule'. A dirty tank with lots of crap, might have algae and high phosphates. Isn't there some studies or tests, or even tanks with 'high' phosphate leves without algae?

 

[jcarlding]

I want to add some plants to my setup.
As I research, I’m considering Posidonia australis, but it doesn’t appear to grow very tall.
I would love something that can grow in a tall column in a rear corner as I have a quite high tank (36”)

any suggestions?

 

[Cory]

phosphate and nitrate will grow algae provided there isnt anything just as efficient as algae to consume it. Algae needs competition to lose the growth game. Corals can do that in significant numbers.

 

[kilnakorr]

phosphate and nitrate will grow algae provided there isnt anything just as efficient as algae to consume it. Algae needs competition to lose the growth game. Corals can do that in significant numbers.

I wonder why this is only 'true' happening in salt water tanks and not freshwater / planted tanks?

 

[Randy Holmes-Farley]

Hi

Brand new to the saltwater arena.
Comming from heavy planted freshwater aquariums, I can't help wonder why I keep read and hear that nitrate and especially phosphates causes algae.
Are there any scientific papers on this?

The same thing was considered a rule in freshwater for many years, but now proven not to be true. In fact, in planted tanks the opposite is true. Lack of these causes algae.

Basically, to much decaying organic matter is the reason for algae outbreaks, and elevated nitrates/phosphates are result of this.

Soooo, anyone done tests or have experiences with algae and phosphates levels?

Foods are the primary source of N and P in a reef tank (at least not one using raw tap water), and it doesn't matter much if they are eaten or not.

Algae will thrive if MANY things are ALL in place, including a sufficient source of N, P, a dozen different trace elements, a place to grow, and freedom from herbivores.

The freedom from herbivores is often the best way to deal with algae, since we are simultaneously wanting to get all the same other things to corals and macroalgae.

 

[Randy Holmes-Farley]

I wonder why this is only 'true' happening in salt water tanks and not freshwater / planted tanks?

Organisms that normally grow on coral reefs, including algae, are adapted to nutrient poor water and are very good at taking them up.

We also are poor at providing natural foods to corals (such as plankton), and so often must rely on elevated levels of nitrate and phosphate to avoid problems.

 

[kilnakorr]

Organisms that normally grow on coral reefs, including algae, are adapted to nutrient poor water and are very good at taking them up.

In both salt and fresh water are algae able to grown and reproduce in nutrient poor water.

We also are poor at providing natural foods to corals (such as plankton), and so often must rely on elevated levels of nitrate and phosphate to avoid problems

I undestand. So it is a misconception that elevated phosphates causes algae?
I could be, as in planted fresh water tank, that dirty tanks causes algae, and phosphates are simply a measureable by product of the dirty tank?

 

[Lucas815]

Nitrate and phosphate are basically food for plants, algae and corals.

A little bit of nitrate and phosphate is good.
Too much is bad.

Corals don't use much nitrate and phosphate, but they still need it in some amount.

Freshwater plants use more nitrate and phosphate than corals, so it's easier to achieve a balance, but the tank still needs a balance. You will still have algae problems in freshwater if you feed too much, and do not have enough plants.

Either in freshwater or saltwater, algae are the "scavengers" of nitrate and phosphate, and will happily use whatever excess is left and reproduce accordingly. The more excess, the more algae.

Recommended values for a mixed reef are 5ppm Nitrates, and 0.05ppm phosphate.

 

[kilnakorr]

Freshwater plants use more nitrate and phosphate than corals, so it's easier to achieve a balance, but the tank still needs a balance. You will still have algae problems in freshwater if you feed too much, and do not have enough plants.

Not true. Unless you mean feed the fish to much. If dosing phosphates or nitrates it is much better to dose too much than too little.
Having 2 ppm or 6 ppm phosphates doesn't matter, and won't have any impact on algae.
This is the point of my question; do elevated phosphates cause algae in saltwater or is it a misconception?

 

[Randy Holmes-Farley]

I undestand. So it is a misconception that elevated phosphates causes algae?
I could be, as in planted fresh water tank, that dirty tanks causes algae, and phosphates are simply a measureable by product of the dirty tank?

No, not at all. 1 ppm nitrate and phosphate will not cause any more algae than 0.1 ppm, because both levels are sufficient and that is all that matters. At either level, something else is likely limiting the growth.

What is sometimes misunderstood is that one cannot always reduce nutrients low enough to limit algae growth (especially some problem types of algae) without simultaneously starving certain corals unless special steps are taken to provide other food sources of N and P (such as amino acids).

In essence, we are trying to supply corals with an unnatural level of nitrate and phosphate) and are trying to deal with the fallout on algae growth.

 

[Lucas815]

Not true. Unless you mean feed the fish to much. If dosing phosphates or nitrates it is much better to dose too much than too little.
Having 2 ppm or 6 ppm phosphates doesn't matter, and won't have any impact on algae.
This is the point of my question; do elevated phosphates cause algae in saltwater or is it a misconception?

I'm currently fighting an algae outbreak for the last month in my saltwater tank.

I got a new fish 2 months ago, that I started overfeeding because it was rather finicky and wanted to give him more opportunities to eat.

Got a lot more detritus and poop, that started decaying in my refugium because the microfauna couldn't keep up, and made my nitrate/phosphate explode to 5 times the normal values.

Boom, cyanobacteria outbreak, red slime everywhere.

 

[Randy Holmes-Farley]

In both salt and fresh water are algae able to grown and reproduce in nutrient poor water.

I don't see a reason to debate this. It's a matter of semantics of what nutrient poor means.

 

[tvan]

So to limit algae growth limits coral growth. The real question is how do I limit it in a display? I feel if you need to provide an environment outside the display tank, sump, scrubber. Algae is a natural filter we should embrace, just outside the display.

 

[Lucas815]

So to limit algae growth limits coral growth. The real question is how do I limit it in a display? I feel if you need to provide an environment outside the display tank, sump, scrubber. Algae is a natural filter we should embrace, just outside the display.

Refugium in the sump + Chaeto macroalgae + Grow light = awesome

 

[kilnakorr]

Got a lot more detritus and poop, that started decaying in my refugium because the microfauna couldn't keep up, and made my nitrate/phosphate explode to 5 times the normal values.

Boom, cyanobacteria outbreak, red slime everywhere.

Yes. Detritus, poop etc.
I wonder if the algae outbreak would have happened if the same nitrate and phosphate levels were reached with nitrate and phosphate additives.

I don't see a reason to debate this. It's a matter of semantics of what nutrient poor means.

I find it important as a newbie, to not get false or inaccurate information. Especially, if it contradicts other information.