Live microalgae (phytoplankton) for aquarium bioremediation? Anyone test this notion?

[Reef Nutrition]

Let's start a discussion!
1. Does live phytoplankton that we add to our tank outcompete nuissance algae for nutrient, restricting its growth? Anyone have any tests they've done on this?
2. Does live phytoplankton that we add to our tanks take up significant/testable amounts of nitrate and phosphate? Anyone have any tests they've done on this?
3. Does live phytoplankton stabilize pH? Tests anyone?

These notions that live phytoplankton can be used to bioremediate a tank are prevalent in the hobby and we aren't aware of any tests that have been done to back up the claims. We sell a live phytoplankton product, but consider it only as a feed and not as a water quality stabilizer/remediation device; however, if live marine microalgae is effective at taking up significant amounts of nitrate and phosphate, we would like to know!!

We fully understand that what goes in must come out, so when I say that phytoplankton "removes" nitrate and phosphate, I am assuming that it is reproducing in the tank and then getting striped out by filtration. Just because the algae is taking up nutrient doesn't mean that the nutrient is now gone from the system; it's just inside the phytoplankton cell for the time being.

I look forward to everyone's thoughts on this!

Chad

 

[AlexG]

I think this is an interesting discussion topic. The testing of this would need to be setup with some good controls in place to prove or disprove the hypothesis. Source water with a known level of nitrates and phosphates would need to be passed through a phytoplankton reactor at different rates and then filtered to remove the phytoplankton before being tested to see if the results support the hypothesis.

I think that practical application of using phytoplankton if it works for your intended purpose in a home aquarium would be an interesting puzzle to solve.

 

[Reef Nutrition]

@AlexG Interesting idea about a plankton reactor.

I hope others see this thread and chime in. We need to flush out this notion (being used by some as fact) that phytoplankton can be poured into our reef tanks for not only feeding our animals, but also for cleaning up water. I don't know anyone that can say without a shadow of a doubt that feeding live phytoplankton resulted in nuisance algae reduction, pH buffering and removal of significant amounts of nitrate and phosphate.

This kind of "matter of fact" information must be picked apart.

Chad

 

[leahfiish]

Following along!

 

[leahfiish]

Following along!

 

[jaws789832]

These are just my unscientific and inconclusive results. I do add live Phyto to my tank. About 30ml every 3 days but it is more to feed my sponges and others. I do not notice a drop in nitrates or phosphates. and there is no PH difference that I can note. The day after I add it my skimmer is noticeably greener so most of it is just getting skimmed out. When I add it I turn off my return pump or a few hours to let it circulate in the DT, after that I assume most of it gets filtered out. My question was always, in order to grow phyto you have to add nutrients (nitrates and phosphates in the form of fertilizer f/2) to the culture vessel. so how much of this is actually still in the solutions that we buy as live phyto. I have actually never tested it so I might in theory be adding nitrates and phosphates every time I dose with phyto.

 

[AlexG]

@AlexG Interesting idea about a plankton reactor.

I hope others see this thread and chime in. We need to flush out this notion (being used by some as fact) that phytoplankton can be poured into our reef tanks for not only feeding our animals, but also for cleaning up water. I don't know anyone that can say without a shadow of a doubt that feeding live phytoplankton resulted in nuisance algae reduction, pH buffering and removal of significant amounts of nitrate and phosphate.

This kind of "matter of fact" information must be picked apart.

Chad

I have been thinking about building a phytoplankton reactor for a while now. I am still in the idea stage of this reactor and I have seen a similar device before that I believe was created in Europe. Since my system has such a high water volume ~1600 gallons I wanted to devise a method of providing a continuous feeding system of phytoplankton using the water from the system to supply the phytoplankton reactor. The idea as it stands now would first run the tank water through a course pre-filter then into a UV sterilizer. Some of the water from the output of the UV sterilizer would be diverted to a fine pre-filter which would then drip into the phytoplankton chamber which would then drip into the main system or into other reactor chambers to grow pods. I think the challenges would be to maintain a constant supply of sterile water and get the correct volume of an established phytoplankton colony that would be able to grow at an acceptable water drip rate that would not deplete the phytoplankton colony.

If phytoplankton could measurably reduce nitrates and phosphates I believe that a reactor like this might be able to test the hypothesis if the idea for the reactor works.

After thinking more about the idea of using phytoplankton to reduce nitrates and phosphates I would be interested to see what kind of research on phytoplankton in the ocean as been done in relation to this subject.

 

[Reef Monkie]

After thinking more about the idea of using phytoplankton to reduce nitrates and phosphates I would be interested to see what kind of research on phytoplankton in the ocean as been done in relation to this subject.

I don't know about research on phytoplankton in the ocean to reduce nitrates and phosphates but there is research on the opposite of that, algal blooms that are thought to be caused by favourable conditions for phytoplankton are being studied. From what I understand phytoplankton in the ocean are nitrogen and Iron limited as well as phosphorous in some instances when those limits are (temporarily) removed these blooms occur because the copepods that feed on phytoplankton have longer generation times so can't initially keep up with their expansion in growth. I also don't think that phytoplankton are perfect organism when it comes to metabolising so they also produce waste, I was reading a article about DOC (Dissolved Organic Carbon) and it stated that in the ocean phytoplankton were one of the main producers of DOC.

 

[Reef Nutrition]

Too bad we haven't heard from the individuals and companies that claim live phytoplankton can be used to bioremediate an aquarium. I was hoping they would have some concrete evidence. We will need to just assume that it doesn't work until someone proves it does! There is still time for proponents of bio remediation via phytoplankton to chime in! I'm dying to hear more.

Chad

 

[Bryn]

Interesting topic. I have no evidence to add to this topic, but have read about such claims, found them interesting, and plausible but gave not much further thought. I'm playing with the idea of a coral only tank, such as a frag tank, and feeding the corals only Copepods, rotifers, and phytoplankton to support the rotifers and copepods. Peoples thoughts on this feeding regime would be appreciated.

Maybe it all comes down to what our idea of the perfect DT is. Most people want a perfect crystal clear water, and work towards controlling this via filtration, both mechanical and natural. Maybe if we changed the color of water from crystal to green, then we could plausibly measure trends in nutrient up take.

Thoughts?

 

[Rakie]

Phyto dosing is all the rage in Italy -- Nobody i've seen doses like that outside of italy.

 

[DSC reef]

It would be nice to see a detailed study of bioremediation with phyto. I dose your live phyto every couple days to feed the entire tank so if I get extra benefits then that's great. Haven't had any negatives that's for sure. We also use the live phyto to gut load live brine shrimp before we feed the tank.

 

[Reef Nutrition]

Interesting topic. I have no evidence to add to this topic, but have read about such claims, found them interesting, and plausible but gave not much further thought. I'm playing with the idea of a coral only tank, such as a frag tank, and feeding the corals only Copepods, rotifers, and phytoplankton to support the rotifers and copepods. Peoples thoughts on this feeding regime would be appreciated.

Maybe it all comes down to what our idea of the perfect DT is. Most people want a perfect crystal clear water, and work towards controlling this via filtration, both mechanical and natural. Maybe if we changed the color of water from crystal to green, then we could plausibly measure trends in nutrient up take.

Thoughts?

Excellent thoughts. We would most certainly need to significantly "green" the water with algae biomass for it to take up considerable amounts of nitrogenous waste; then you have to get the algae out of there. Also, adding live phytoplankton from a culture to a tank at high density also means you are adding an organism that also excretes waste; and, you would need to have very dense algae cultures so that you aren't adding too much phytoplankton from your cultures because the culture water itself contains phosphates and nitrates, among other things that are used to grow marine microalgae. Ugh! It would be a tough thing to experiment with, especially since all tanks are different. Macro algae will still be the most effective method to remove nitrogenous waste and phosphate, naturally, but it too has it's upsides and downsides.

I think it's a great idea to add/feed phytoplankton, rotifers and copepods to a coral only tank - a darn good idea.

Chad

 

[iwishihadgills]

I feel like you would have to remove filter socks and turn of the skimmer. Would be interesting to seen some one heavily dose a tank with phyto for a couple of days and then filter it off and see how it change the parameters. Could be dangerous though if the phyto crashed.

 

[iwishihadgills]

Plus the corals would probably go nuts

 

[keddre]

sounds like an interesting idea, I have seen these claims before though. I haven't tested it (altough I probably could) but I could imagine that it would. There is research that shows phyto needs phosphate and nitrogen to survive, so it makes sense (shallowly) that if one shoots enough phyto into a tank, and has a way to "harvest" said phyto, then we would be able use it to significantly reduce nitrate and phosphate.

In practice this becomes a problem because phyto is used in your tank at some point, where it later gets formed into poop. I think the prior scenario would only work in a tank where there is nothing that uses phyto (so an empty tank?) or to outdose whatever consumes the phyto. Could be a fun experiment

 

[Reef Nutrition]

sounds like an interesting idea, I have seen these claims before though. I haven't tested it (altough I probably could) but I could imagine that it would. There is research that shows phyto needs phosphate and nitrogen to survive, so it makes sense (shallowly) that if one shoots enough phyto into a tank, and has a way to "harvest" said phyto, then we would be able use it to significantly reduce nitrate and phosphate.

In practice this becomes a problem because phyto is used in your tank at some point, where it later gets formed into poop. I think the prior scenario would only work in a tank where there is nothing that uses phyto (so an empty tank?) or to outdose whatever consumes the phyto. Could be a fun experiment

Very good point. The phytoplankton is getting consumed and turned into waste as it's trying to remove the waste. There's a paradox for you.

Many of us would like to see someone do this; but, it needs to be done very professionally, utilizing quality test kits. One thing to keep in mind is that phytoplankton doesn't just consume nitrogen and phosphate. Since they are photosynthesizers and fix carbon from carbon dioxide, the result is a significant reduction in CO2 and a subsequent rise in pH. If you aren't buffering, you could stress out the animals in the tank. Phytoplankton also need things like iron, so if the nutrients in the system are limiting, then the culture will simply crash in the tank and pollute it. The whole thing could be very tricky, and since all tanks are different, there's really know way to say that "one size fits all", so to speak.

What is more, the concentration of algae in the culture needs to be high. You don't want to add too much of the culture media to the tank as well. With this method, it's also possible that, with enough highly dense phytoplankton added at one time, the nitrates and phosphates would be gobbled up more rapidly, helping to avoid a crash before you are able to remove it from the system.

A protein skimmer and high density foam filter would pull out the phytoplankton pretty quick if the equipment is adequate for the system and the waste. Carbon would help as well. Probably UV?

Chad

 

[GreshamH]

This is a non starter. No need to test it via a tank... you know what a dense culture uptakes, simply do the math. FWIW it won't pan out in favor of those saying the addition of a small amount of semi dense culture reduces phosphates or nitrates. It's all marketing hype and no substance.

 

[Js.Aqua.Project]

I did this sort of thing on accident once....

I cultured phtyo near my tank and when cutting my cultures would pour some into my (old) 125. One day I apparently went a little too far overboard...

Usually my NO3 and PO4 sat around 10-20ppm and .08-.16 respectively. During and immediately after this accidental bloom both registered 0.

Tried initially using some Cherrystone Clams (by some I mean like 40) to consume the phyto - they put a dent in the density but didn't clear it up.

Ended up needing a UV sterilizer to clear up the phyto...

Here is the thread from that experience:
https://www.reef2reef.com/threads/phyto-bloom-in-a-home-aquarium.284726/

 

[Bryn]

I did this sort of thing on accident once....

I cultured phtyo near my tank and when cutting my cultures would pour some into my (old) 125. One day I apparently went a little too far overboard...

Usually my NO3 and PO4 sat around 10-20ppm and .08-.16 respectively. During and immediately after this accidental bloom both registered 0.

Tried initially using some Cherrystone Clams (by some I mean like 40) to consume the phyto - they put a dent in the density but didn't clear it up.

Ended up needing a UV sterilizer to clear up the phyto...

Here is the thread from that experience:
https://www.reef2reef.com/threads/phyto-bloom-in-a-home-aquarium.284726/

To most European divers, that's great visibility...