Nitrate and Phosphorus Control via Phytoplankton Additions?

[erk]

Exactly what I was thinking. I always thought tank water has too much microbial life that will out compete and consume the photo.

I was thinking this would happen as well, but figured this was an experiment. If it did die off then I learned my lesson. But I'm not seeing any appreciable die off. Cultures are still flourishing... when they aren't nutrient restricted. Just need to tune the dosing regimen to ensure harvesting enough every week.

I would like to eventually do an automatic phyto dosing system, but the thing I am trying to reconcile is how to deal with the volume of phyto in the dosing tube. If you do a continuous drip system 24/7, its not a big deal as long as the tubing is short enough. Too long and the phyto will start to settle before they get to the end. If you only dose during a specific time, then the phyto stuck in the tubing will die. Maybe need a way to suck the phyto back. Now I'm adding in a dosing pump. Now two pumps, one for dosing phyto, the other to pull top off water.

Second issue is dosing rates to ensure you don't crash the culture. I get around this by switching which culture I dose. You could setup inlet and outlet 3 way, or N-way for N-1 cultures, solenoid valves/manifolds and use a microcontroller to switch between cultures. Becomes very complex with a lot of failure mechanisms. Not impossible by any means, but if I was to make something this complex, I will need to add in a lot of redundancies.

So for my system and dosing regimen, I would need two dosing pumps, one for top off that doesn't need any special coding. The second dosing pump for sending phyto to the tank would need to be coded to pull back the volume of phyto in the tubing every evening. There would be two 3-way solenoid valves, one for top off, one for dosing. I would code the controller to switch between cultures every 7 days. I'm going to stick with my manual method for now. I want to make sure phyto dosing is what I want to do long term before I spend time and money to develop an auto dosing system.

 

[Mortie31]

I would like to eventually do an automatic phyto dosing system, but the thing I am trying to reconcile is how to deal with the volume of phyto in the dosing tube. If you do a continuous drip system 24/7, its not a big deal as long as the tubing is short enough.

Just use a simple short overflow tube to dose the phyto to your tank. Use a dosing pump to add fresh salt water to the phyto container, which will cause a rise in the level which will simply overflow into your tank @sixty_reefer did this in his automatic phyto reactor

 

[erk]

Just use a simple short overflow tube to dose the phyto to your tank. Use a dosing pump to add fresh salt water to the phyto container, which will cause a rise in the level which will simply overflow into your tank @sixty_reefer did this in his automatic phyto reactor

I like that idea. Essentially cuts the amount of equipment I need in half.

 

[salty joe]

Well, what do you know, using the correct amount of sodium thiosulfate made a big difference. I went form a secchi depth of around 30 to a secchi depth of around 20. That's splitting the culture in half every eight days.
I'm going to increase the light and see if I can get the same result in four days.

 

[John Biddle]

Great thread everyone, thanks, I'm learning a lot. One person asked if anyone is cleaning their phyto before dosing but didn't get an answer, so I'd like to repeat the question and ask a couple more related ones.

Does anyone know of a way to concentrate phyto? The many phyto products for sale are all highly concentrated so I know it can be done, but I don't know how. I'm currently culturing nanno and it will go right through the 53 micron screens I see for sale, and these are the smallest I've found. I have seen some 10 micron cloth for sale for a DIY setup, but since nanno is much smaller than that it doesn't seem like that would work either.

Cleaning would eliminate any possible issues with the N & P from the fertilizer and concentrating would let me keep a safety batch in the refrigerator.

 

[shred5]

Great thread everyone, thanks, I'm learning a lot. One person asked if anyone is cleaning their phyto before dosing but didn't get an answer, so I'd like to repeat the question and ask a couple more related ones.

Does anyone know of a way to concentrate phyto? The many phyto products for sale are all highly concentrated so I know it can be done, but I don't know how. I'm currently culturing nanno and it will go right through the 53 micron screens I see for sale, and these are the smallest I've found. I have seen some 10 micron cloth for sale for a DIY setup, but since nanno is much smaller than that it doesn't seem like that would work either.

Cleaning would eliminate any possible issues with the N & P from the fertilizer and concentrating would let me keep a safety batch in the refrigerator.

I always let it settle out some in a refrigerator and remove the top water.

I heard of some people trying centrifuges and you have to be very careful because they can damage the cells..

 

[Matt Carden]

Great thread everyone, thanks, I'm learning a lot. One person asked if anyone is cleaning their phyto before dosing but didn't get an answer, so I'd like to repeat the question and ask a couple more related ones.

Does anyone know of a way to concentrate phyto? The many phyto products for sale are all highly concentrated so I know it can be done, but I don't know how. I'm currently culturing nanno and it will go right through the 53 micron screens I see for sale, and these are the smallest I've found. I have seen some 10 micron cloth for sale for a DIY setup, but since nanno is much smaller than that it doesn't seem like that would work either.

Cleaning would eliminate any possible issues with the N & P from the fertilizer and concentrating would let me keep a safety batch in the refrigerator.

I read somewhere on here filter through a coffee filter

 

[User]

Great thread everyone, thanks, I'm learning a lot. One person asked if anyone is cleaning their phyto before dosing but didn't get an answer, so I'd like to repeat the question and ask a couple more related ones.

Does anyone know of a way to concentrate phyto? The many phyto products for sale are all highly concentrated so I know it can be done, but I don't know how. I'm currently culturing nanno and it will go right through the 53 micron screens I see for sale, and these are the smallest I've found. I have seen some 10 micron cloth for sale for a DIY setup, but since nanno is much smaller than that it doesn't seem like that would work either.

Cleaning would eliminate any possible issues with the N & P from the fertilizer and concentrating would let me keep a safety batch in the refrigerator.

For nanno, settling and removing the upper water layer is the only practical way for a hobbyist. (Like @shred5 said) -They are 1.5um in diameter, so not much available to filter them out,

Also the amount of N and P in the phyto should be negligible if you use it about a week after the last fertilizer dose. The cells will use it as the grow. Besides- You’d have to be dosing huge volumes compared to your tank volume for it to make any difference.

It sounds weird, but concentrating a plateau phase culture and storing it will actually negatively impact culture recovery at a later date. Your better of just saving 1-200ml of straight non-concentrated culture for archive.

 

[User]

Well, what do you know, using the correct amount of sodium thiosulfate made a big difference. I went form a secchi depth of around 30 to a secchi depth of around 20. That's splitting the culture in half every eight days.
I'm going to increase the light and see if I can get the same result in four days.

What’s the purpose of the sodium thiosulfate?

 

[John Biddle]

@neilp2006 I did see that initiating a culture from a refrigerated sample would probably take a little longer, probably due to phyto becoming accustomed to their new environs, but if I was successful concentrating I could store a lot more in a small space and fridge space is at a premium, with phyto not high on the list. Where have I gone wrong?

BTW, how long would it likely take to settle to say 1/4?

 

[Greg P]

Would 1 of you please condense the last 10 pages for the rest of us just joining the conversation?
Thanks everyone!!

 

[Greg P]

IE
Purpose, tests, results, dosing procedures etc

 

[sde1500]

Would 1 of you please condense the last 10 pages for the rest of us just joining the conversation?
Thanks everyone!!

IE
Purpose, tests, results, dosing procedures etc

No. Not that hard to skim through yourself.

 

[User]

@neilp2006 I did see that initiating a culture from a refrigerated sample would probably take a little longer, probably due to phyto becoming accustomed to their new environs, but if I was successful concentrating I could store a lot more in a small space and fridge space is at a premium, with phyto not high on the list. Where have I gone wrong?

BTW, how long would it likely take to settle to say 1/4?

The issue is that many algae species release small molecule messenger molecules that work to convey population density to the ‘group’. When you concentrate, then store, they continue to produce the molecules, but now at a much higher local concentration due to the reduced water volume. They then shut down a lot of metabolism genes that’ll take time to turn back on. Concentrating to about 4x, then diluting back up to 1x, will add two-three days into the back end of the new culture, compared to diluting a 1x stock to 1:3 and growing that. The benefit here is that the culture will also be more robust due to the younger metabolic state of the cells

Nannochloropsis is a negatively charged algae, so they are very efficient at repelling each other and staying in suspension. I’ve noticed it’ll take 2-3 days in the fridge to settle to minimum level, about 3/4” for a 1 gallon container. The compacted volume of a healthy culture is actually surprisingly thin. Saying that, that represents like a 20x concentration, so 4x might only take 12-18 hours.

 

[User]

No. Not that hard to skim through yourself.

Lol

 

[Greg P]

No. Not that hard to skim through yourself.

Ya, thanks for the help

 

[Greg P]

Lol

Skimming through 10 pages with your kids in toe is your fun Neil?
I was only looking for a brief

 

[Dan_P]

The new 120-gallon reef tank is doing well and I've added all the fish I feel prudent for now (2-Yellow Tangs, 1-Lamarck's Angel, 2-Maroon Clowns, 2-Ocellaris clowns, 2-Neon Gobies - about 20 inches total length in all and growing.) These fishes are fed at least 3x daily with frozen mysis, live adult brine shrimp and nauplii, frozen 'meaty' fish foods, an algae-based frozen food, two types flake foods, two types pellet foods. Nori seaweed (attached to a clip) is added in the morning for the Tangs. About 25 coral fragments have been added. These are fed ReefRoids and a similar product from Germany (Fauna Marin). These are soaked in Selcon, coral feeding stimulator and amino acid supplement from Polyp Lab, and a VitaChem product. Since some of the corals I have are omnivores, I add at least 250 milliliters of phytoplankton daily as well. This is added several times a day. The Goniopora specimens are growing as are all others - there are also some feather-dusters that arrived on the live rock that are demonstrating good growth. Since the protein skimmer would remove the phytoplankton, it is on a timer and runs only at night. I was concerned that nitrate and phosphorus concentrations would spike using this routine but to my surprise their concentrations have dropped to the lowest levels seen in this tank. I speculate that the phytoplankton mops up nutrients during the day and those not consumed are removed by the protein skimmer at night. I should add that I use a Hach colorimeter and EPA-approved reagents. Nitrate is reported to a tenth of a part per million (presently 0.7 ppm); Phosphorus to a hundredth part per million (now 0.02 ppm.) I can't state absolutely that the phyto addition is responsible and it could be coincidental that nutrient concentrations began to drop when phyto additions began. But...

Following this interesting idea.

The conjecture that phytoplankton additions are controlling nitrate levels raises the following questions for me. How large is the phytoplankton population in the aquarium? How rapidly is it depleted? How well do they grow at low nitrate and phosphate levels? What is the increase in the number of phytoplankton? Does iron play a role in the effectiveness of phytoplankton to sop up nutrients? How rapidly do they settle out in the aquarium? Is there an induction period for nutrient uptake when the phytoplankton are suddenly depleted of nutrients?

An offline experiment might shed some light on the question “for a given population size, light level, and nitrate and phosphate concentration, how quickly are the nutrients depleted? When I get tired of studying cyanobacteria and dinoflagellates, I know where to find my next research project

 

[tripdad]

I believe the OP's theory was that the increased biodiversity that the phyto was feeding was actually responsible for the nutrient( N&P) reduction, not the phyto itself.

 

[User]

Skimming through 10 pages with your kids in toe is your fun Neil?
I was only looking for a brief

Not sure exactly how to respond to that. Can’t tell if your upset or not.

But hey- I’ve got a 1 year old that’s teething and taking 20 minute micro naps between 7pm-5am, and a three year old that doesn’t like going to bed so runs around the hallway for an hour, yet I managed to catch up and even contribute. Fun? Not really, but I still did my reading myself since a lot of info gets lost when complete strangers summarize a complicated subject. What they might think is fluff, might actually be useful information.

But ok, if you don’t have time to read it:

Tiny plant cells into tank
Nutrients drop
Cause and effect
Biodiversity increase depleted nitrients
How to condense culture for storage?
Gravity settling
Should I? Benefits? Cons?
‘Contaminating’ fertilizer. Levels too low after dilution, no need to worry. Also- correct timing ensures fertilizer utilized before put in tank

How’s that?