Nitrates vs phosphates for algae growth

[Miami Reef]

Hello. I want to grow nuisance algaes in my reef tank to outcompete Dino’s.

I got Dino’s because my nutrients went to 0 for a few weeks while in fallow period.

Anyway I have fish and I’m really feeding heavily. My phosphates is 0.07 and my nitrates are 0.2ppm.

Does phosphates or nitrates have a greater impact on algae growth? If I have 0 PO4 and high NO3, would that have a greater impact on algae growth, or will high NO3 and 0 PO4 grow algae better?


I’m trying to know if nitrates could be a limiting factor in algae growth. Even if phosphates were high.

Also, are some foods higher in nitrates than others?

 

[Quietman]

I'm not sure you can out compete dinos which is the main problem once you have them. Certain species can reproduce amazingly fast (doubling in 20 minutes and I don't think that's much of an exaggeration). That 's why UV for battle has to be at least 8x tank volume per hour, getting ahead of the reproduction rate is tough.

Only way I was successful ultimately was UV and DinoX (warning DinoX wiped out any corals and 3 fish that were already stressed from the Ostreopsis outbreak).

I have no good news to report on dinos. Good luck!

 

[Miami Reef]

I'm not sure you can out compete dinos which is the main problem once you have them. Certain species can reproduce amazingly fast (doubling in 20 minutes and I don't think that's much of an exaggeration). That 's why UV for battle has to be at least 8x tank volume per hour, getting ahead of the reproduction rate is tough.

Only way I was successful ultimately was UV and DinoX (warning DinoX wiped out any corals and 3 fish that were already stressed from the Ostreopsis outbreak).

I have no good news to report on dinos. Good luck!

The Dino’s are actually going away! I just want to hit the nail on the coffin with beneficial algaes!

 

[Dan_P]

Hello. I want to grow nuisance algaes in my reef tank to outcompete Dino’s.

I got Dino’s because my nutrients went to 0 for a few weeks while in fallow period.

Anyway I have fish and I’m really feeding heavily. My phosphates is 0.07 and my nitrates are 0.2ppm.

Does phosphates or nitrates have a greater impact on algae growth? If I have 0 PO4 and high NO3, would that have a greater impact on algae growth, or will high NO3 and 0 PO4 grow algae better?


I’m trying to know if nitrates could be a limiting factor in algae growth. Even if phosphates were high.

Also, are some foods higher in nitrates than others?

If you have a new system, it might just be a matter of time before algae starts to grow, even without messing with PO4 or NO3 concentrations.

Algae use more nitrate than phosphate. How much nitrate they use depends on the amount of light and CO2 that is available. You can blast algae with bright light but if not much CO2 is available, they won’t take up much nitrate. If trace elements are low, which slows algae growth, nitrate use will be low. There are no “general” rules, just algae need multiple things to grow.

 

[Spare time]

Hello. I want to grow nuisance algaes in my reef tank to outcompete Dino’s.

I got Dino’s because my nutrients went to 0 for a few weeks while in fallow period.

Anyway I have fish and I’m really feeding heavily. My phosphates is 0.07 and my nitrates are 0.2ppm.

Does phosphates or nitrates have a greater impact on algae growth? If I have 0 PO4 and high NO3, would that have a greater impact on algae growth, or will high NO3 and 0 PO4 grow algae better?


I’m trying to know if nitrates could be a limiting factor in algae growth. Even if phosphates were high.

Also, are some foods higher in nitrates than others?

Ignore nitrate for algae growth. Nitrogen is almost never the limiting factor and really is only an issue at 0.00 as cyano likes this environment (that plus enough phosphate).


Dinos seem to occur when phosphate hits 0, regardless of nitrate levels. Raising phosphate back up usually seems to fix things. I have dealt with dinos, and have helped many others get rid of them. I am not sure why many see dinos as this threat that can't be defeated.




For all other algae in our tanks, Phosphate appears to be the limiting factor. It never has anything to do with too much white light, too much nitrate, etc. It appears to always be phosphate.

 

[Cory]

If you want to get green algae dose some iron. Iron is usually the limiting element. In the ocean desserts blow iron rich dust into the sea and kick start a phytoplankton bloom.

 

[attiland]

Hello. I want to grow nuisance algaes in my reef tank to outcompete Dino’s.

I got Dino’s because my nutrients went to 0 for a few weeks while in fallow period.

Anyway I have fish and I’m really feeding heavily. My phosphates is 0.07 and my nitrates are 0.2ppm.

Does phosphates or nitrates have a greater impact on algae growth? If I have 0 PO4 and high NO3, would that have a greater impact on algae growth, or will high NO3 and 0 PO4 grow algae better?


I’m trying to know if nitrates could be a limiting factor in algae growth. Even if phosphates were high.

Also, are some foods higher in nitrates than others?

First ID your dinos with microscope to have proper ide which treatment you need.
You need both nitrate and phosphate in detectable levels.
Depends on which type you have the treatment is different. could be UV , silicates dosing, bacterial treatment or combination of many.

 

[dvgyfresh]

I would dose neo nitro to raise nitrate , want it to be 10x higher than phosphate otherwise encourages nuisance algae growth

 

[Spare time]

I

I would dose neo nitro to raise nitrate , want it to be 10x higher than phosphate otherwise encourages nuisance algae growth

I doubt the ratio matters. What should matter is if there is enough for whatever process the algae needs it for. They only need a certain amount to get things done, regardless of the ratio present in the water

 

[Randy Holmes-Farley Verified Community Expert]

Algae need a sufficient amount of N and P and lots of other things (e.g., iron and manganese).

If any one of those is present in sufficient quantity, then having more of it (2x or 1,00x) will not make it grow faster, because something else is limiting to growth.

I agree that ratios are not the best way to think of it, and can be absurdly misleading. Absolute values are far more useful.

 

[Miami Reef]

I just did a 30% water change in the past 2 days (15% each day). I am confident that there’s no limiting nutrients in my tank. I’m already seeing the green again!

I can’t believe I’m saying this! This is absurd!

Happy reefing.

 

[Miami Reef]

Algae need a sufficient amount of N and P and lots of other things (e.g., iron and manganese).

If any one of those is present in sufficient quantity, then having more of it (2x or 1,00x) will not make it grow faster, because something else is limiting to growth.

I agree that ratios are not the best way to think of it, and can be absurdly misleading. Absolute values are far more useful.

Question: despite my water changes and 2ppm silicates I’m not seeing any diatom nor sponge growth. Do you think lack of carbon could contribute to this? I didn’t dose carbon for a few months.

 

[Randy Holmes-Farley Verified Community Expert]

Question: despite my water changes and 2ppm silicates I’m not seeing any diatom nor sponge growth. Do you think lack of carbon could contribute to this? I didn’t dose carbon for a few months.

Diatoms do not need any organic carbon.

They may be limited by something else, but it is also possible that if the SI reading is from ICP and not a silicate test, it may be due to a form of silicon that diatoms do not readily consume.

 

[Miami Reef]

Diatoms do not need any organic carbon.

They may be limited by something else, but it is also possible that if the SI reading is from ICP and not a silicate test, it may be due to a form of silicon that diatoms do not readily consume.

Well, I didn’t actually measure Si. I just purchased the same bottle you mentioned in your article and dosed 2ppm following your calculations.

 

[Miami Reef]

Oops. It’s 5ppm

 

[Randy Holmes-Farley Verified Community Expert]

Ah, OK, now I understand the issue.

I'd wait a few days, and dose again, and repeat a few times.

If there are not many diatoms currently present, they will need some time to expand to noticeable numbers.

 

[Cory]

If you habe a microscope you can look to see their numbers. I got one for dinos that was 100 ish and its very good. Just get one with a glass eyepiece if you do.

 

[attiland]

Used one is about £30 on eBay if you want to save some money.

 

[Miami Reef]

I do have a microscope. I haven’t checked recently, but last week I saw a few diatom cells in the midst of trillions of Dino cells. This was before the silicate 2ppm dosage. I was expecting a bloom by now.

I bet if I microscope it now I’d see more diatoms than before.

 

[Miami Reef]

I also sent out my first ICP test. I’m interested to know what’s with my tank’s nutrients.