Nitrate and Phosphorus Control via Phytoplankton Additions?

[Dana Riddle]

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...

 

[Ebslinger]

Following, hoping to learn more here.

 

[cancun]

I am also following.....very interesting....I have grown my own phyto for years....I add a little daily....but only turn the skimmer off for a hour or two. I have a 200 gallon tank....but never thought about phyto possibly lowering nitrates.....hmmmmmm.....

 

[Dana Riddle]

I forgot to mention that the phyto culture is fertilized with Gulliard's f/2 formula and has high nitrate concentrations - last time I checked nitrate as N exceed the instrument's upper limit (5.5 ppm as N, or 24.2 ppm as NO3.) So, in addition to heavy feedings, the phyto addition adds nitrate. Haven't checked phosphorus.

 

[Ebslinger]

Question, you mentioned you added 250 ml of phytoplankton throughout the day... is that done on a doser or manually?

2, 3, 4 times a day?

if my math is correct (which it rarely is), that's about .48 ml per gallon, per day...?

 

[Dana Riddle]

Question, you mentioned you added 250 ml of phytoplankton throughout the day... is that done on a doser or manually?

2, 3, 4 times a day?

if my math is correct (which it rarely is), that's about .48 ml per gallon, per day...?

At least 2x manually during the day. The frozen fish food is thawed in green water too. The phyto culture is so 'thick' that the water in the 120 is tinted green for a few minutes.

 

[Ebslinger]

This is fascinating to me. It makes total sense... the ocean runs on phytoplankton... it is the basis of all life in the ocean.

Can't wait to learn more.

Could dosing .5 ml (per gallon) of phytoplankton be the cure for Nitrate and Phosphate?

Looking forward to seeing your phosphorus test results.

 

[Dana Riddle]

This is fascinating to me. It makes total sense... the ocean runs on phytoplankton... it is the basis of all life in the ocean.

Can't wait to learn more.

Could dosing .5 ml (per gallon) of phytoplankton be the cure for Nitrate and Phosphate?

Looking forward to seeing your phosphorus test results.

I checked the phyto culture water. The phosphorus test turns blue if P is present and it turned a dark blue in seconds (reaction time is normally 2 minutes) so dilution was required. Result: 0.77 ppm as P, or 2.36 as PO4 (!). Nitrate as N is 0.9 ppm, or 3.8 ppm as NO3. It has been much higher (>5.5 ppm as NO3-N.) Another note: Some sort of protozoa are apparent on the glass, and the Lamarck's Angel constantly picks at the rock (I assume it is eating protozoa.) At night, the water swarms with protozoa. Even though water testing says N and P are low, it is actually a high nutrient system where these elements are sequestered by algae and protozoa.

 

[cancun]

Very interesting! I use that same fertilizer! I am anxious to learn more! How much fertilizer do you add to your phyto?

 

[Dana Riddle]

I checked the phyto culture water. The phosphorus test turns blue if P is present and it turned a dark blue in seconds (reaction time is normally 2 minutes) so dilution was required. Result: 0.77 ppm as P, or 2.36 as PO4 (!). Nitrate as N is 0.9 ppm, or 3.8 ppm as NO3. It has been much higher (>5.5 ppm as NO3-N.) Another note: Some sort of protozoa are apparent on the glass, and the Lamarck's Angel constantly picks at the rock (I assume it is eating protozoa.) At night, the water swarms with protozoa. Even though water testing says N and P are low, it is actually a high nutrient system where these elements are sequestered by algae and protozoa.

 

[Ebslinger]

Second Question, you mention culture water, but do you have display tank water parameters as well? Did I miss them? I probably did. Doing to many things at once.

Interested to see dosed parameters vs DT parameters... are the little phytoplankto eating it all?

 

[sixty_reefer]

It does makes wonders wend the doses are consistent, I’ve been dosing phytoplankton on a automated system for just over an year now, I think the only tricky part for me is to get the nitrates up to balance the system, did try and use the ATI nutrition N but my dose was at almost 60m daily to just try and keep the nutrients uptake balanced, obviously had to stop that way as I was looking at close to 40$ a month just to keep my tank stable. The solution will be potassium nitrate but is not readily available to me. Just tough id mentioned as it may be something you may want to introduce at later stage.

 

[Dana Riddle]

It does makes wonders wend the doses are consistent, I’ve been dosing phytoplankton on a automated system for just over an year now, I think the only tricky part for me is to get the nitrates up to balance the system, did try and use the ATI nutrition N but my dose was at almost 60m daily to just try and keep the nutrients uptake balanced, obviously had to stop that way as I was looking at close to 40$ a month just to keep my tank stable. The solution will be potassium nitrate but is not readily available to me. Just tough id mentioned as it may be something you may want to introduce at later stage.

Are you culturing phyto or buying it by the bottle? I paid $10 or the initial culture and about that for the Gulliard's formula and presently have 60 gallons (!) under culture. Some of that will be dedicated to rotifer culture - have rotifer eggs but haven't had time to hatch them yet.

 

[Ebslinger]

@sixty_reefer Ya, I wouldn't encourage you to stockpile Potassium nitrate unless you want the FBI at your door.

 

[Dana Riddle]

Second Question, you mention culture water, but do you have display tank water parameters as well? Did I miss them? I probably did. Doing to many things at once.

Interested to see dosed parameters vs DT parameters... are the little phytoplankto eating it all?

The DT water is 0.7 ppm N and 0.01 P, down from 1 and 0.17 respectively. The nitrate method I use (cadmium reduction) is sensitive to chloride hence my report is low. I *think* the phyto is scrubbing the water of nutrients. Another thing, a 4" Pyramid Butterfly disappeared but ammonia concentrations never went up (0 as ionized ammonia (Seneye) and zero by the EPA-approved Hach salicylate method). It's remains eventually make itself known.

 

[KrisReef]

If these observations pan out it could spell the end for the old school refugium.
Thanks for posting!

 

[sixty_reefer]

@sixty_reefer Ya, I wouldn't encourage you to stockpile Potassium nitrate unless you want the FBI at your door.

It’s a good thing I don’t live in the states [emoji6]

 

[sixty_reefer]

Are you culturing phyto or buying it by the bottle? I paid $10 or the initial culture and about that for the Gulliard's formula and presently have 60 gallons (!) under culture. Some of that will be dedicated to rotifer culture - have rotifer eggs but haven't had time to hatch them yet.

I use a continuous in tank culture, basically consists of a reservoir in the refugium area that pulls 3ml of tank water every 60 minutes by a doser and den it drops 3 ml of phytoplankton in the tank by gravity. Also got the doser set to drop 2ml of fertiliser every 7 days. Basically a full automated phytoplankton system the only labour I got to do is to is to adjust salinity every 14 days to compensate evaporation.

Looks a bit like this wend it was connected to a continuous rotifers culture.

I was able to go as high as 9ml per hour (216ml per 24h) but had to bring it down again due to not be able to increase nitrates and dinos were just setting in at 0 readings.

At the time I done this sketch I was using a reservoir with a lower salinity to make it all work.

I just find it stress free also don’t really have space in the apartment to have a normal culture going [emoji23]

 

[Dana Riddle]

If these observations pan out it could spell the end for the old school refugium.
Thanks for posting!

Fish stocking up. Nutrients added via fish/coral feeding as well as nutrients in the phyto culture water, but DT nutrients (N & P) at an all time low.

 

[Dana Riddle]

I use a continuous in tank culture, basically consists of a reservoir in the refugium area that pulls 3ml of tank water every 60 minutes by a doser and den it drops 3 ml of phytoplankton in the tank by gravity. Also got the doser set to drop 2ml of fertiliser every 7 days. Basically a full automated phytoplankton system the only labour I got to do is to is to adjust salinity every 14 days to compensate evaporation.

Looks a bit like this wend it was connected to a continuous rotifers culture.

I was able to go as high as 9ml per hour (216ml per 24h) but had to bring it down again due to not be able to increase nitrates and dinos were just setting in at 0 readings.

At the time I done this sketch I was using a reservoir with a lower salinity to make it all work.

I just find it stress free also don’t really have space in the apartment to have a normal culture going [emoji23]

Innovations such as yours have made the hobby what it is today. I look back at some of the issues we faced in the late 80s/90s - problems that had to be resolved and are taken for granted today. Still a lot to learn though.