Phytoplankton as a nutrient export method

[DrDirt]

Curious if anyone has ever actually tracked how nutrient levels are affected by dosing live phytoplankton into their aquariums. Assuming a protein skimmer actually removes phytoplankton, and that there is nutrient uptake to some degree as it grows in the aquarium, it would seem conceptually that it would not add significantly to nutrient levels.

Yes I am aware that there are many claims that it can help manage nutrient levels, but I am skeptical of how much a relatively small amount of phytoplankton would actually help, more curious if it hurts.

 

[Subsea]

“Yes I am aware that there are many claims that it can help manage nutrient levels, but I am skeptical of how much a relatively small amount of phytoplankton would actually help, more curious if it hurts.“

Not sure if @Danna Riddle is active on this site anymore? He had a 55G continuous culture of phytoplankton and with that much phytoplankton available, he lowered nutrients in his system, I assume by using a protein skimmer. I do not own a protein skimmer and I operate 1000G of marine systems.

I have a 30G phyto culture outside in filtered sunlight. When I add 2G of phyto to 75G display with numerous filter feeders; water is stained green and 2 hours later, it is crystal clear. I dose when lights come on. I have unopened test kits that are expired, so don’t ask for test results. If I need to know numbers, I send water to a regional agriculture lab.

 

[Mr. Mojo Rising]

I've been adding phyto my tanks for years, I honestly don't see any difference from when I don't add it.

I would not believe that it lowers nitrate and phosphate without evidence. Its a strong claim, therefore it needs strong evidence, but there is none.

 

[Subsea]

I've been adding phyto my tanks for years, I honestly don't see any difference from when I don't add it.

I would not believe that it lowers nitrate and phosphate without evidence. Its a strong claim, therefore it needs strong evidence, but there is none.

I suggest you pursue Dana Riddle. He will give you evidence.

@Mr. Mojo Rising
What constitutes evidence to you? I don’t think it is a strong claim at all. If ATS algae filter is used for nutrient export, why wouldn’t ”green water” export nutrients using protein skimmer?

Or, if I grow ornamental macro algae in my display and prune & sell it, does that export nutrients? Just curious, how you see this.

 

[Mr. Mojo Rising]

comparing macro algae and phytopankton is apples and oranges.

I understand how macro algae works, it makes sense to me, I can see the results with my eyes.

As mentioned, I've been adding phyto on and off to my tanks for years (excessive amounts because I culture myself so I just pour or it in), its not lowering my nitrate, not in a measureable amount anyway.

The OP is asking for evidence, he is asking if "anyone has tracked how nutrient levels are affected".

I'm also asking for evidence, and just giving my 2 cents that I've been adding phyto but have never seen this evidence myself.

 

[Subsea]

comparing macro algae and phytopankton is apples and oranges.

I understand how macro algae works, it makes sense to me, I can see the results with my eyes.

As mentioned, I've been adding phyto on and off to my tanks for years (excessive amounts because I culture myself so I just pour or it in), its not lowering my nitrate, not in a measureable amount anyway.

The OP is asking for evidence, he is asking if "anyone has tracked how nutrient levels are affected".

I'm also asking for evidence, and just giving my 2 cents that I've been adding phyto but have never seen this evidence myself.

Dana Riddle has written books and is an expert on reef aquarium husbandry. The information is available if you wish to pursue it.

@Randy Holmes-Farley
Are you familiar with Dana Riddle experiment with phytoplankton?

 

[DanyL]

For this to work or at the very least be measurable you’ll need abundant amounts of phyto in the tank, and for its growth rate to exceed the export rate so that it would actually have an opportunity to consume nutrients before being removed.

In a “pour in” constellation - it would probably won’t have enough time actually grow before it’s skimmed/filtered out of the system, and thus even if there were any changes in nutrient consumption - it would be unmeasurable, or within a normal deviation range.

However, I believe that in a continuous feeding constellation there is actually a good chance that it would work, because the water would be saturated enough with phyto so that the export rate will be lower than the growth rate of the phyto.

But it’s all talk and theory, I haven’t seen any evidence to prove this claim thus far.

 

[Subsea]

“In a “pour in” constellation - it would probably won’t have enough time actually grow before it’s skimmed/filtered out of the system, and thus even if there were any changes in nutrient consumption - it would be unmeasurable, or within a normal deviation range.”

I doubt that could be proved to be correct. I don’t agree with the statement. And who decides what a normal deviation is?

 

[DanyL]

“In a “pour in” constellation - it would probably won’t have enough time actually grow before it’s skimmed/filtered out of the system, and thus even if there were any changes in nutrient consumption - it would be unmeasurable, or within a normal deviation range.”

I doubt that could be proved.

That’s exactly the point I tried to illustrate here.

Even if there was any change in consumption - would you be able to measure it without any interference?

And even if you tried to isolate it in a test group - would that be a good representation of what happens in a diverse system where a good percentage of phyto might be consumed by its inhabitants while at the same time also being exported out of the system?

I believe the answer to this would be no, you will not be able to prove or disprove this claim in a “pour in” constellation.

 

[Subsea]

That’s exactly the point I tried to illustrate here.

Even if there was any change in consumption - would you be able to measure it without any interference?

And even if you tried to isolate it in a test group - would that be a good representation of what happens in a diverse system where a good percentage of phyto might be consumed by its inhabitants while at the same time also being exported out of the system?

I believe the answer to this would be no, you will not be able to prove or disprove this claim in a “pour in” constellation.

I dose large quantities of phyto > 2G into 75G tank that is 25 years mature, display is full of invert filter feeders that include sponges, flame scallops & feathers of many colors. Phyto is dosed when lights come on and tank water is stained green; 2 hours later the water is crystal clear. I do not own a protein skimmer so, I recycle..

I don’t care if it’s nutrient recycling or export, it works for me.

 

[DanyL]

I dose large quantities of phyto > 2G into 75G tank that is 25 years mature, display is full of invert filter feeders that include sponges, flame scallops & feathers of many colors. Phyto is dosed when lights come on and tank water is stained green; 2 hours later the water is crystal clear. I do not own a protein skimmer so, I recycle..

I don’t care if it’s nutrient recycling or export, it works for me.

Oh I have no doubt that it’s beneficial to the system, I tried to approach the question as scientifically as I could (and I’m far from being qualified to do so lol).

I plan myself to build some sort of a continuous feeding pytho monstrosity for my frag tank, without any consideration of it being helpful in nutrient export - but more to be able to absorb what’d be the impact on coral growth and coloration, specifically aiming at SPS, and maybe also to try and utilize it as a biological CO2 scrubber for my skimmer.

Nice tanks btw, love it!

 

[Subsea]

Oh I have no doubt that it’s beneficial to the system, I tried to approach the question as scientifically as I could (and I’m far from being qualified to do so lol).

I plan myself to build some sort of a continuous feeding pytho monstrosity for my frag tank, without any consideration of it being helpful in nutrient export - but more to be able to absorb what’d be the impact on coral growth and coloration, specifically aiming at SPS, and maybe also to try and utilize it as a biological CO2 scrubber for my skimmer.

Nice tanks btw, love it!

Actually, Dana has a continuous feed of phytoplankton, which uses uv treated display tank water as makeup.

 

[GARRIGA]

Not salt but single cell algae all perform the same. This was an experiment using plants that could float to see if it would filter a 75 with four 2" Oscars that were fed 8-10 daily. Water was tested every other day with simple strips as I wasn't seek precision and just the presence of ammonia, nitrites or nitrates. Assumption being that if nitrates were zero then so was phosphates as plants need both. Turns out that even with 1/6 the tank devoted to high filtering plants I still got green water. What reefers call phyto. Water remained green yet my parameters tested remained zero. This was the only time I was able to maintain green water as in all other experiments it would crash and require a new culture or addition of plant food. I concluded that the feeding and co2 produced by the fish were sufficient to keep the green water going. Also concluded that if either was limited then it would crash. Hope was to use green water to provide both the filtration, oxygen and food source for raising discuss fry and clownish.

One assumption I had was to introduce green water to mop up nutrients periodically then filter them out with a sediment filter of a low enough micron. This would work as an export option. Reading shows that the Chinese would culture their goldfish outdoors in the summer in green water.Apparently providing benefits of which I'm not sure and likely purely anecdotal but so is much of our hobby. Live green water cultures are easy enough to start. Some plant food and water in a jar on the window sill all that's needed. Plus easy to acquire and it also feeds the pods one likely has already.

 

[Doctorgori]

one issue I’ve had dosing photo is dosing the F2 (nutrients) along with the algae … you can time it so the fertilizer is at the lowest/algae growth is maximum, but inevitably a lil NPK makes it into the tank ….
…and IME lil chance the phyto can mutltiply fast enough to make any dent in a established tank, too many mouths

 

[Subsea]

one issue I’ve had dosing photo is dosing the F2 (nutrients) along with the algae … you can time it so the fertilizer is at the lowest/algae growth is maximum, but inevitably a lil NPK makes it into the tank ….
…and IME lil chance the phyto can mutltiply fast enough to make any dent in a established tank, too many mouths

In my cultivation system, phyto density doubles every 5 days. When I harvest, I add modified f/2 fertilizer from Mercer of Montana & liquid seaweed concentrate from kelp.

 

[KrisReef]

I wonder if the uptake of phyto from hungry coral would count as export of nutrients. A skimmer moves stuff into a cup but the corals are still in the tank. How to measure all of this, is the challenge.

If we use plant growth as a measurement, assuming growth requires nutrient uptake, does uptake = export?

In one sense there is no way phyto could work but in another there is no way it can't. Experimental design is the key to answering the question of what is accomplished, and where?

 

[Subsea]

one issue I’ve had dosing photo is dosing the F2 (nutrients) along with the algae … you can time it so the fertilizer is at the lowest/algae growth is maximum, but inevitably a lil NPK makes it into the tank ….
…and IME lil chance the phyto can mutltiply fast enough to make any dent in a established tank, too many mouths

Considering that I run high nutrient systems, I dose nh4 to keep up with nitrogen demand and the more trace minerals from the phytoplankton; the better.

 

[Subsea]

I wonder if the uptake of phyto from hungry coral would count as export of nutrients. A skimmer moves stuff into a cup but the corals are still in the tank. How to measure all of this, is the challenge.

If we use plant growth as a measurement, assuming growth requires nutrient uptake, does uptake = export?

In one sense there is no way phyto could work but in another there is no way it can't. Experimental design is the key to answering the question of what is accomplished, and where?

Nutrient recycling runs the ecosystem. When desirable biomass gets crowded, then frag & sell.

 

[KrisReef]

Nutrient recycling runs the ecosystem. When desirable biomass gets crowded, then frag & sell.

That's always nice when you have a measurable export in biomass!

 

[DanyL]

Actually, Dana has a continuous feed of phytoplankton, which uses uv treated display tank water as makeup.

I know there were some attempts at doing it this way, and I considered it for awhile.

But eventually I concluded that keeping a separate container with clean saltwater wouldn’t be too time consuming on my hand, and it’d be easier to achieve under the budget I set for this project.

But.. maybe as a future upgrade? Its definitely something I’d like to fiddle with someday.