PNS PROBIO and Carbon dosing

[reefluvrr]

Hello @Kenneth Wingerter and anyone that can share thoughts or their experience of using PNS Probio as a bacteria source in carbon dosing?

From my readings about PNS Probio, it appears that R. palustris is a possible strain of bacteria that can be beneficial to the coral holobiont.

Please correct me if I am understanding incorrectly; R. palustris much prefer to be in anerobic conditions.
However, R. palustris can be aerobic in water suspension and are chemoautotrophic for carbon dosing thus reducing nitrogen and phosphate? How efficient is this mechanism of action in our reef tank environment?

My main goal is to control my phosphate level while feeding/seeding my corals "good holobiont" bacteria R. palustris as opposed to "bad" bacteria (vibrio, dinos,etc).


Thanks!

 

[Kenneth Wingerter]

Hello @Kenneth Wingerter and anyone that can share thoughts or their experience of using PNS Probio as a bacteria source in carbon dosing?

From my readings about PNS Probio, it appears that R. palustris is a possible strain of bacteria that can be beneficial to the coral holobiont.

Please correct me if I am understanding incorrectly; R. palustris much prefer to be in anerobic conditions.
However, R. palustris can be aerobic in water suspension and are chemoautotrophic for carbon dosing thus reducing nitrogen and phosphate? How efficient is this mechanism of action in our reef tank environment?

My main goal is to control my phosphate level while feeding/seeding my corals "good holobiont" bacteria R. palustris as opposed to "bad" bacteria (vibrio, dinos,etc).


Thanks!

Yes, R. palustris is definitely responsive to carbon dosing. It can utilize ethanol, but prefers acetate. In the absence of a suitable organic carbon, it additionally can switch to an autotrophic mode and utilize CO2. It's pretty adaptable in that respect. It even possesses enzymes necessary to degrade cellulose (unlike most organisms), and so can even consume the poorly digestible detritus that accumulates from dead algae.

It prefers, but doesn't require, anaerobic conditions. It's known as one of the most oxygen-tolerant purple non-sulfur bacteria. In fact, it can live quite happily as an aerobic heterotroph. It's flagellated and highly motile, and swims quite effectively in the water column. It's even chemotactic toward sources of organic carbon, and swims right after them. So again, it certainly could be used for carbon dosing in the traditional sense. However, depending upon the unique microbiological community in a given aquarium system, it may or may not be able to compete with other, obligately aerobic, bacteria in the plankton.

All that being said, R. palustris is most competitive as an anaerobic photoheterotroph. It thrives in anoxic areas of the aquascape that receive some light (deep pits in live rock, just beneath the upper layer of the sand bed, within pockets of detritus, etc.). This means that it consumes organics (whether dosed or existing as wastes) along with ammonia/nitrite/nitrate and phosphate WITHOUT consuming oxygen. In other words, the presence of this bacterium not only enhances carbon dosing, but also reduces the risk of oxygen depletion.

This bacterium is extremely effective at sequestering nitrogen and phosphorus. Actually, it's used in wastewater treatment plants to remove phosphate at crazy high levels we would never see in an aquarium. Cool thing about nitrogen use... In nutrient-poor environments, it can actually fix nitrogen as you indicated. This species has indeed been found living in association with reef-building corals. The corals actively take up these bacteria, and in some regions have a higher preference for them seasonally--where ammonium is less available to their zooxanthellae in certain months than in others. They may grow in both the coral gut and mucus, feeding on organic exudates from the coral as well as the zooxanthellae. It has well-known anti-vibriotic properties and thus almost certainly reduces the incidence of diseases such as RTN.

Despite its overall versatility, this bacterium does have an Achilles heel. It cannot synthesize its own B vitamins, but requires them for growth, and therefore must obtain them from its environment. Depending upon what you feed, what you supplement, what kind of chem filtration you use, etc., your aquarium may or may not have abundant reserves of free vitamin B floating around. This is why the companion product PNS YelloSno is useful. In addition to serving as a coral food, it's rich in B vitamins, and so promotes growth of PNS ProBio. (AlgaeBarn just made the combo available in a reduced-price package.)

On a final note... You mentioned that you wish to target phosphate. One advantage of using this particular microbe for that purpose is its ability to fix nitrogen. Specifically, you don't need to worry about Redfield ratios; if nitrogen becomes the limiting nutrient, R. palustris will simply fix its own and continue to aggressively sequester phosphorus without interruption.

Hope this helps!
Ken

 

[reefluvrr]

Thank you very much Ken for the information. I had to reread it a few times to understand and appreciate the versatility of this bacteria.

You mentioned that you wish to target phosphate. One advantage of using this particular microbe for that purpose is its ability to fix nitrogen.

This is my 'aha moment' ! I do not have to worry about nitrate dosing to help get my phosphates down.
Hans-Werner from Tropic Marin feels it is not to necessary Nitrate dose our reef tanks.

I am trying out Tropic Marin carbon dosing formula Elimi-NP since my Phosphate was 0.26 two days ago and today is down to 0.2 after using an initial quadruple dose of PNS Probio on Friday. I believe the carbon source is made from organic carbon such as kelp derivative.

In the past, I did not have much luck reducing phosphate without increasing my carbon dose and Nitrate.

My only filtration is an oversized protein skimmer.
Can I put the PNS ProBio on my apex DOS doser? If so, any recommendation for amount/gallon?


I have dosed Dr. Tim's Waste Away and have noticed a drop in ORP and decrease in pH upon turning off protein skimmer a couple hours later in the past.
However, I did not see my ORP drop nearly as much with PNS Probio even after a couple hours. I do not know what this means though if anything.
My current pH in my system hovers between 8.4 to 8.55. My pH with PNS Probio did not drop much either.
You explained that the anerobic form of R. palustris can utilized carbon without depleting oxygen.
Does the free swimming form of R. palustris use oxygen during carbon metabolism to help reduce Nitrate and Phosphate?

This is why the companion product PNS YelloSno is useful. In addition to serving as a coral food, it's rich in B vitamins, and so promotes growth of PNS ProBio. (AlgaeBarn just made the combo available in a reduced-price package.)

I actually got the combo package. Can I add PNS YelloSno for the Vitamin B together with PNS ProBio at the same time to help with my carbon dose regime?

Any suggestion on how to better utilize the PNS products with the copepods and phytoplankton?

Thank you!

 

[Kenneth Wingerter]

Amazing how fast these bacteria can assimilate phosphate, isn't it?

I actually don't recommend using PNS ProBio in a doser, being as it can form biofilms that might muck it up. Aside from that, I view dosers as unnecessary for this product, since it's seemingly impossible to overdose. I've applied 40X overdoses to zoas in my test system and they didn't even flinch.

Yes, it's possible for the motile cells ("swarmers") to behave as straight chemoorganoheterotrophs, and they may be induced to do so aerobically in a copiotrophic environment. R. palustris naturally occurs in shallow ocean waters. But these bacteria swim away from oxygen when it can be avoided; in the wild, planktonic forms of PNS bacteria are most abundant at around 35 meters (95 feet) depth--still some light, but considerably less oxygen.

Again, it's not that they can't survive in the upper water column, it's just that they aren't well-equipped to compete with the obligately aerobic bacterioplankton there. So they "retreat" to oxygen-depleted zones where they can wield the advantage of phototrophy and diazotrophy (they can neither carry out photosynthesis nor fix nitrogen in the presence of free oxygen). They still do assimilate nutrients much in the same way that the aerobic heterotrophs do, albeit preferably in anoxic environments.

You absolutely can use ProBio and YelloSno simultaneously. The directions suggest alternating them, but this is really just to level out the food intake for corals and other filter-feeders. When using the combo primarily for nutrient management, concurrent dosage makes plenty of sense.

I can't think of any special applications for these products when used with pods and phyto. I can say though that there are some advantages to using them together. For example, both ProBio and YelloSno nutritionally enrich the pods, making them more wholesome to the animals that eat them. Transfers carotenoids (from ProBio) up the food chain, too. Another cool thing is that this bacterium consumes polyphenols and other yellowing compounds that are exuded by the phyto. I also suspect (still researching this one) that it degrades DMSP (produced by phyto as well as macroalgae and zooxanthellae), which would be a pretty big deal. Whether or not aquarists know it yet, haha. Maybe good reason to commercialize Roseobacter someday...

Anyway, thanks for the great questions.

 

[reefluvrr]

So they "retreat" to oxygen-depleted zones where they can wield the advantage of phototrophy and diazotrophy (they can neither carry out photosynthesis nor fix nitrogen in the presence of free oxygen). They still do assimilate nutrients much in the same way that the aerobic heterotrophs do, albeit preferably in anoxic environments.

If I find my Phosphate resistant to going down further after a couple weeks, I will try using a sponge seeded with R. palustris in a corner of my sump.

Thank you very much for taking your time and providing me with good explanations!

I am looking forward to what your future research shows about dimethylsulfoniopropionate (DMSP).

Thanks again!

 

[Kenneth Wingerter]

Yes! I totally wanted to suggest that exact same thing (soaking sponge, putting it in an area of low flow), but didn't want to be too wordy haha. I'd further suggest placing it in an area that receives some light (doesn't have to be intense).

One other dosing method to try is adding it to fish food (increases food conversion, and so reduces waste, and therefore potentially reduces phosphate output).

You're quite welcome, thanks again for the really good questions. I hope to hear updates.

 

[reefluvrr]

Hi @Kenneth Wingerter

It has been one month where I would like your input on how I should approach my mistake.

I truly thought that I could let my NO3 drop without worries while my PO4 was still around 0.08.
When I started to get 0 NO3 and 0.08 PO4, my glass pane started to develop green algae.
I started to lose some LPS with polyp retraction and some SPS started to STN.

I suspect some other greater reason to which I don't understand with NO3 and PO4 ratio imbalances.

I unfortunately continued to try and reduce PO4 without NO3 addition and that was when Dino's started to develop.
I then started to panic and dumped a boat load of NO3 to the tune of 16ppm.

I am now trying to follow PSXerholic "redfield" ratio of PO4 to NO3 but have not gotten to that idea ratio yet.

Right now I still have plenty of Dino's and my current PO4 is 0.26 while my NO3 is at 8ppm.

My goal is to bring my NO3 to 2ppm while PO4 drop down to 0.1

I am waiting for a new bottle of PNS Probio this Friday.
In the meantime, any suggestion would be greatly appreciated with dosing PNS Probio in getting rid of Dinos?

Thank you.

 

[Kenneth Wingerter]

Hi, and thanks for your patience.

I’d start by saying that my word is hardly the last word on the subject of nutrient sequestration in recirculating aquarium systems. But I hope some of the following is helpful!

The first thing I’d say is that I personally wouldn’t get too wrapped up in any effort to “balance” nitrogen and phosphorus per Redfield’s ratio. This ratio is NOT necessarily a “normal” or “ideal” ratio of nitrogen and phosphorus in all natural ecosystems; it rather is the recipe for phytoplankton. In other words, this ratio is ideal for phyto and other algae, but not necessarily for corals and other reef animals. Wait, but what about zooxanthellae, you might ask...

In reality, natural seawater very often has different ratios than this (giving us the concept of limiting nutrients). Actually, I’ve scoured many scientific papers looking for “normal” nitrate and phosphate concentrations for reef ecosystems; all I learned is that there are no “standard” values for these parameters. They vary from site to site, and may even vary from within a particular site according to season.

One thing, however, seems to be the norm in zooxanthellate coral reef habitats: Oligotrophy. While reefs do tend to be nitrogen-limited, both nitrogen and phosphate are typically in very low supply. This I think is important to remember, as it is the reason that coral reefs can be coral reefs in the first place; if nitrate and phosphate levels are high, benthic algae grows unchecked and (as I’m sure you already know) outcompetes corals and most other sessile inverts. The take-home, I think, is that nutrient concentrations (low ones, to be most specific) are way more critical than nutrient ratios when it comes to promoting a coral-friendly environment. Far better to have oligotrophic (especially low-N) conditions with a slightly imbalanced Redfield ratio than to have eutrophic (especially high-N) conditions with a “perfectly balanced” ratio.

That’s not to say that nitrogen deficiency and phosphorus deficiency are equivalent. To the contrary, it appears that phosphorus deficiency is considerably more stressful to the coral holobiont (most specifically to the zooxanthellae). Again, “deficiency” is relative in the Redfield sense, as a deficiency of phosphorus may be brought on by an excess of nitrogen.

Again, I don’t wish to present confusing or contradictory ideas here; absolutely Redfield ratios matter to corals because they matter to the algae that live within them. The findings in this paper, for example, strongly suggest that phosphorus deficiency (or nitrogen surplus, if you want to look at it that way) can adversely affect coral (i.e. zooxanthellae) health. What I’m trying to point out is that ratio AND concentration matter. And low nitrogen in particular seems to be key. Corals seem to be pretty well adapted to N starvation (especially compared to P starvation). And, nitrogen limitation appears to be the very thing that keeps clear water/coral reefs from becoming green water/algal turfs.

It’s interesting that you had a green algae bloom just as your NO3 tests began to read zero. This is a common paradox in our hobby. Why would a bloom occur (especially green algae, which in general are most nitrogen-hungry) just as your nitrates drop to undetectable levels? The test kit offers a snapshot that measures concentration in a given moment, but cannot reveal anything about rates of production/assimilation. It’s certain that an abundance of dissolved inorganic nitrogen was being produced in your tank; the algal bloom couldn’t occur otherwise. Indeed, the reason that your nitrate concentrations were so low were very possibly BECAUSE of aggressive uptake by the algae. Sure, the algae were simultaneously sequestering phosphate as well, but there apparently was an excess in input (perhaps from foods). Without more info, though, I find it a lot harder to explain exactly how your phosphate concentration more than tripled soon after ADDING nitrate.

Honestly, you did what I would’ve done (considering the growth of green algae) when you attempted to reduce PO4 without adding NO3. To condense the above long story into something shorter, I suggest aiming for very low nutrient concentrations overall. Nitrogen in particular should be very low (considerably less than 2 ppm, in my humble opinion). I realize that a lot of hobbyists, including experienced coral farmers, might question that. And it’s true that some enjoy success (in terms of coral growth rates) with elevated nutrient levels. But this comes with the price of potentially horrendous nuisance algae blooms. These systems generally require intensive mitigation in the form of UV and/or ozone sterilization, massive algivorous CUCs, etc.

I think something closer to nature is preferable: A situation where nutrients (especially NO3) are maintained at very low concentrations OUTSIDE the coral, but are nevertheless maintained at optimal concentrations WITHIN the coral. Part of this of course is possible due to the efficient N recycling between corals and zooxanthellae. But relatively recent research has shown that the high productivity of coral reefs owes primarily to symbiotic relationships between corals and nitrogen-fixing bacteria (zooxanthellae cannot fix nitrogen!). We’ve already established why corals cannot thrive in eutrophic environments (overgrowth by algae); nitrogen fixation (especially by rhizobial bacteria (Family Bradyrhizobiaceae)) explains why corals can grow so prolifically in oligotrophic environments.

The bacteria in PNS ProBio (Rhodopseudomonas palustris) are rhizobia and have indeed been shown to benefit corals in this manner. It’s too simple to say merely that they fix nitrogen and thereby fertilize the coral’s zoothanthellae. In reality, they do more than that: They actively regulate nitrogen concentrations. This is because they preferentially take up excess nitrogen (whether ammonia, nitrite, nitrate or nitrogenous organic compounds) from the environment. They only fix nitrogen when nitrogen is in extremely short supply. Only makes sense right? Makes more sense energetically to grab a slice from the pizza that’s already on the table than to go make another slice from scratch.

All this makes these microbes AT LEAST as beneficial in captive systems (where NO3 is much more often in a state of excess) than in nature.

So, why are they mainly doing this inside the coral, but not everywhere in the tank? There are at least three reasons for that, actually. First, they prefer anaerobic environments (and they can carry out nitrogen fixation only in anaerobic conditions). Sure, this can be deep in the substrate, within passive flow biomedia, etc., but also deep within the coral’s gut and mucus. Second, they prefer an organic source of carbon (which is plentiful with the coral’s gut and mucus). Third, while they can survive in the dark, they are photosynthetic and prefer strongly photic conditions (and zooxanthellate corals are always exposed to intense sunlight). For these reasons, these microbes may be hundreds of times more abundant in the coral’s tissues than in the surrounding water column.

This brings us to the dinos… maybe. There are many, very different, species of dinoflagellates that can grow in aquaria. Some can be particularly frustrating to eliminate because they’re either heterotrophic or mixotrophic. In other words, you can control NO3 all you want, but they’ll still grow so long as there is some form of nitrogenous organic matter present (I’ve seen this with hobbyists that feed heavily, especially those that don’t strain out the juice from frozen foods, or overdosing aminos).

I can think of at least a couple cases where people have reported a reduction of dino growth after using PNS ProBio. HOWEVER, it’s difficult to ascribe causality in these cases. In at least one of these cases, the individual simultaneously tried multiple methods of control. I’d say that IF this bacterium helps to control dinos, it most plausibly is through competition for organic carbon as well as for nutrients. One more thing--dinos do often live in close association with nitrogen fixers; however, dinos are obligately aerobic, and therefore are far more likely to live closely to aerobic nitrogen fixers (i.e. cyanobacteria) than to anaerobes such as R. palustris.

Though I didn’t necessarily give conclusive answers to all of your questions, I hope that I’ve given you a little more insight into what MIGHT have happened! But I wrote a lot of stuff here in a short amount of time and certainly might have forgotten some points or not have explained some things as well as I could have. So please let me know if any of this requires elaboration or clarification!

In terms of dosage, I’d just use as directed (per directions on the bottle). But I’d also suggest adding the doses directly to your fish foods and especially to any coral foods you might use.

Also, please stay in touch and update!

 

[reefluvrr]

Hi Kenneth,

Thank you very much for taking your time and sharing your knowledge with me. You provided a lot to process.
It will take time for me to reread and analyze before getting my new bottle of PNS Probio.

The findings in this paper, for example, strongly suggest that phosphorus deficiency (or nitrogen surplus, if you want to look at it that way) can adversely affect coral (i.e. zooxanthellae) health.

Can you help me understand what may have happened to my tank from one of my coral experiences prior to using PNS Probio.
My NO3 was about 1 to 2 ppm. My PO4 was hovering around .14 to 0.08. I was carbon dosing to achieve this level. However, my LPS corals (frogspawn, hammers, torches) all shrunk in polyp extension.
To make sure my PO4 level is accurate, I purchased two Hanna ULR meters to do back to back testing. They usually are about 0.02 to 0.04 points from each other.
The LPS were not happy, SPS underwent some STN as well. I could not reduce my PO4 levels below 0.1 without having corals dying.
I suspect that I had too much bacteria (likely the bad kind) in the water column that did something to the corals? (non rhizobial bacteria that affected zooxanthella health?) My guess is I affected somehow the coral holobiont.

Moving forward, when I receive my new bottle of PNS Probio, I will continue to dose PNS Probio and PNS YelloSno per instruction while closely monitoring NO3 levels not allowing it to bottom out.

The bacteria in PNS ProBio (Rhodopseudomonas palustris) are rhizobia and have indeed been shown to benefit corals in this manner.

Hopefully my coral holobiont will repopulate with such beneficial bacteria.

Without more info, though, I find it a lot harder to explain exactly how your phosphate concentration more than tripled soon after ADDING nitrate.

I panicked when dinos appeared. I dosed NO3 up too high to around 10ppm and thought my PO4 red-field levels were too low. Thus I dosed NEOPHOS to bring PO4 to 0.26....

I will report back my findings later.

Thanks for your help and your interest in my case!


















I

 

[Kenneth Wingerter]

Hey, you're quite welcome.

With respect to the issues you once experienced with your LPSs, it's pretty difficult to say for certain what made them angry. In terms of the "too much bacteria" theory, I can offer a couple of possibilities.

Particularly if you were carbon dosing heavily, the corals might've been suffering from minor hypoxia. Most bacterioplankton are aerobes. An aside--PNS ProBio consumes organics (including "dose" carbon sources) from primarily anaerobic sites, and so make carbon dosing safer (in that they also assimilate nitrate, but do so without consuming oxygen). Could also be that some of the bacteria that flourished during dosing in your particular microbiome were "bad" microbes such as Vibrio.

This one is a really wild guess, but one reason you may have had lingering nutrient levels despite the aggressive carbon dosing is that much of the PO4 and NH4/NO3 were trapped in the microbial loop. Especially if you skimming and water change regimen were not equally as aggressive.

Ken

 

[reefluvrr]

Hi Ken,

I want to thank you for hyperlinking articles...that takes your extra time and effort, but most importantly thanks for sharing the knowledge!

I actually oversize the skimmer for my small tank. My pH runs from 8.3 to 8.5 night and day.
However, when I turn off the skimmer to allow bacteria to grow, the pH does drop to 8.0.

I received my bottle of PNS Probio and Yellow Sno yesterday and placed 50ml Probio and 50ml Yellow Sno into my tank this morning. At 5 p.m. today I took the following measurements:

PO4--0.16
NO3--4ppm
Mg--1290
Ca++--450
Alk--8.4

I took these measurements so that I can compare them to an ATI ICP test I sampled at the same time today to be shipped out.

I wanted to pick your brain regarding the following though:

Since I seeded the tank this morning at 9 a.m. with Probio, could the bacteria in the ATI ICP sample continue to utilize the PO4 and NO3 in the test tube samples before they are tested? This would mean lower PO4 and NO3 numbers I assume....


As always thank you!

Alex

 

[Kenneth Wingerter]

They most definitely will keep on assimilating PO4 and NO3, even in the dark and without oxygen. If there's a good number of them in the sample water, and the sample is held for days before testing, then I'd say they could conceivably alter a sample appreciably. One suggestion: This species likes warmth. Its metabolism really slows down as the water cools. So maybe you'd get a "truer" sample to your ICP people if you sent it with a cold pack? This would possibly halt the metabolism of lots of other bugs in the water too and have the same effect on most of them.

 

[reefluvrr]

Hi Ken,

While I am waiting for my results for my ATI ICP test. I tested my NO3 and PO4 this morning after over the weekend.
My PO4 went back up to 0.21ppm and NO3 went up to 6ppm.

I still am battling with dinos but does not seem to be getting worse.

We talked about using a sponge in the sump seeded with PRO Bio with some light if I could not bring my NO3 or PO4 down enough.

However I wanted to pick your brain about using ceramic media seeded with PNS Probio (Brightwell X-port Bio cubes or Marine Pure Ceramic 1.5" Ball) in a large phosban reactor. I can better control flow rate through it.
I wonder about the following:
1. Flow rate
2. allow for light or no light (like a cryptic reactor)
3. is a sponge in a sump still better than media reactor?

Thank you.

 

[Larry L]

I can add one anecdotal data point about PNS Probio and carbon dosing. My tank has been running for about 6 years now, and I have always had trouble with nitrates running in the 20's even though I have a pretty good skimmer, dose vinegar, and have a reverse-lit refugium with Ulva (used to be Chaeto, but the Ulva outcompeted it). My phosphates have always run between 0.100 and 0.200 unless I'm super consistent about dosing lanthanum chloride.

Without changing anything else about my routine, I started doing small daily doses of PNS Probio (about 5 ml per day into an 80 gallon system). After a few weeks to maybe a month, my nitrates started consistently measuring between 4 and 6 instead of in the 20's and have stayed that way for several months now. I haven't noticed a big change in my phosphates. I don't know if a PNSB population has built up or if it's necessary to continue dosing, but I keep dosing because I figure worst case it makes for pretty good coral food.

Yes, R. palustris is definitely responsive to carbon dosing. It can utilize ethanol, but prefers acetate.

I dose vinegar so maybe that explains why things seem to be working so well.

It thrives in anoxic areas of the aquascape that receive some light (deep pits in live rock, just beneath the upper layer of the sand bed, within pockets of detritus, etc.).

I have two of the big MarinePure blocks stacked on top of each other (so basically an 8"x8"x8" cube) and placed in a corner of my refugium area where the water is slower moving. I originally did that intentionally in the hopes of creating a more anoxic area for denitrification to happen. Coincidentally it's also in a spot where it gets lit by my fuge light. I wonder if that makes it a happy place for the PNSB to do their thing.

 

[Kenneth Wingerter]

I wanted to pick your brain about using ceramic media seeded with PNS Probio (Brightwell X-port Bio cubes or Marine Pure Ceramic 1.5" Ball) in a large phosban reactor. I can better control flow rate through it.
I wonder about the following:
1. Flow rate
2. allow for light or no light (like a cryptic reactor)
3. is a sponge in a sump still better than media reactor?

Wow, more great questions. I don't think a sponge in the sump would be inherently better than a reactor (or a DSB, if present). But I'm also not aware that anyone has ever tested these bacteria in a reactor. I've always thought that one big benefit of these bacteria is that they don't necessarily require a reactor (e.g. denitrifying filter). Would a particular type of reactor enhance their growth/promote their activity? Maybe, and worth trying!

I would definitely suggest using light, as this organism's growth rates are highest under photoheterotrophic conditions. As an aside, full-spectrum light is acceptable, but this species prefers blue.

Whether or not I would add an organic carbon source would depend upon the existing organics load. For example, if I ran a large refugium or habitually carbon dosed, I wouldn't add any carbon (at least not until after seeing how the reactor performed without it).

Water flow is trickier. My impulse would be to suggest keeping it down to a trickle as to maintain anaerobic conditions within the reactor chamber (this organism also prefers anoxia). However, these aren't the only microbes in your system of course, and some of the "hitchhikers" (in large enough numbers and under certain conditions) can generate hydrogen sufide, nitrite and other unwanted byproducts. Thus, if I were doing this, I'd start with a reasonably strong flow rate (just enough to maintain aerobic conditions). Nitrifiers and aerobic heterotrophs would coat the outer portion of the media, and that's fine; PNS bacteria would nevertheless flourish in the anoxic microzones deeper within the media.

Over time, you could slowly and incrementally decrease water flow as to make conditions within the chamber more and more favorable for PNS bacteria (all the while testing for nitrite and sniff testing for hydrogen sulfide). You'd eventually know you hit the sweet spot with the flow valve when the telltale evidence of PNS bacteria (specifically under anaerobic, photosynthetic conditions) appear: A reddish-purple biofilm against chamber wall, especially nearest the light source. Again, you could go anaerobic from the start, but in that case I'd test the effluent waters like crazy until satisfied that no nasty substances were being released.

Haha, it just occurred to me that some of the "chaeto reactors" I've seen would work great for this application, filled with biomedia instead of macroalgae.

My last suggestion would be to soak the biomedia with the inoculant as to (1) target the colonization site and (2) promote settlement by maintaining the anaerobic conditions of the cuture medium from the bottle during transfer (same if added to sponge).

 

[reefluvrr]

Ken,

Thanks for the thorough answers!

Haha, it just occurred to me that some of the "chaeto reactors" I've seen would work great for this application, filled with biomedia instead of macroalgae.

Funny, I was going to ask if I should try using my Pax Bellum chaeto reactor, but the reactor puts out about 54w of red and white light. Still worth a try or too much light?

Would you know why a cryptic reactor running in the the dark may help reduce PO4? I was reading about cryptic reactor from Geo reef and there was a sentence saying PO4 can be reduced when using proper media.

 

[Kenneth Wingerter]

Ken,

Thanks for the thorough answers!



Funny, I was going to ask if I should try using my Pax Bellum chaeto reactor, but the reactor puts out about 54w of red and white light. Still worth a try or too much light?

Would you know why a cryptic reactor running in the the dark may help reduce PO4? I was reading about cryptic reactor from Geo reef and there was a sentence saying PO4 can be reduced when using proper media.

Not sure about the cryptic reactor and hard to say without knowing the species of microbes involved.

I'm familiar with the lights in the Pax Bellum and I think they would be great. Actually, this bacterium mainly utilizes light from two spectra (two peaks), the blue as I mentioned but also red. I actually think those lights would be better (i.e. more efficient) than the full spectrum I use, particularly if their reds are closer to the far red. I don't think they'd be too bright.

 

[minus9]

I can add one anecdotal data point about PNS Probio and carbon dosing. My tank has been running for about 6 years now, and I have always had trouble with nitrates running in the 20's even though I have a pretty good skimmer, dose vinegar, and have a reverse-lit refugium with Ulva (used to be Chaeto, but the Ulva outcompeted it). My phosphates have always run between 0.100 and 0.200 unless I'm super consistent about dosing lanthanum chloride.

Without changing anything else about my routine, I started doing small daily doses of PNS Probio (about 5 ml per day into an 80 gallon system). After a few weeks to maybe a month, my nitrates started consistently measuring between 4 and 6 instead of in the 20's and have stayed that way for several months now. I haven't noticed a big change in my phosphates. I don't know if a PNSB population has built up or if it's necessary to continue dosing, but I keep dosing because I figure worst case it makes for pretty good coral food.




I dose vinegar so maybe that explains why things seem to be working so well.



I have two of the big MarinePure blocks stacked on top of each other (so basically an 8"x8"x8" cube) and placed in a corner of my refugium area where the water is slower moving. I originally did that intentionally in the hopes of creating a more anoxic area for denitrification to happen. Coincidentally it's also in a spot where it gets lit by my fuge light. I wonder if that makes it a happy place for the PNSB to do their thing.

Just curious, did you cut your skimmer when daily dosing PNS Probio? If so, for how long?

 

[Larry L]

Just curious, did you cut your skimmer when daily dosing PNS Probio? If so, for how long?

No, too lazy. Sometimes I dump it into the sump right over the Marine Pure blocks, but usually directly into the tank near the return so it gets dispersed.

 

[minus9]

No, too lazy. Sometimes I dump it into the sump right over the Marine Pure blocks, but usually directly into the tank near the return so it gets dispersed.

Thanks! I might try smaller daily or every other day doses? My NO3 is 1ppm or less, but my PO4 is .24ppm on average, so I'm just trying to lower it below 0.2ppm.