We have reached phase 2 of our Biome Cycle investigation where the BRStv team shares the next 10 weeks of our journey to see how each of the established test tanks handles the purposeful introduction of pests.


Biome Cycle Series

Biome Cycle Video Series
Join us as we learn how to beat the ugly stage and develop effective techniques for producing a balanced microbiome in our aquariums.

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"The ugly stage" as we know it exists because of introduced pests that proliferate in relatively vulnerable aquariums. These pests must be introduced and they make their way into your tank alongside livestock or hitchhike on rocks and substrate.

Phase #2

During phase 2, we purposefully dosed each of the 12 test tanks with a slurry of pests collected from all of the test tanks. The idea is to put all of the 12 test tanks on the same playing field in terms of the presence of diatoms, dinoflagellates, algae, cyanobacteria, and chrysophytes.

Through the experiment, each of the 12 tanks continued to receive a standard photoperiod with light output levels suitable for SPS corals. We dosed the slurry twice on week 15 and performed a manual cleaning of all the tanks on week 21 to see how the pests bounced back after human interference.   

  • Do the pests resolve themselves and reach a balance?
  • Which, if any, pests turn into persistent and ongoing problems?
  • When one pest goes away, does another replace it?
  • Does the presence of pods and microcrustaceans have an effect on pests?
  • Can we draw any conclusions from biome balance scores collected toward the end of phase 1?

AquaBiomics Microbiome Biome Balance Scores from Phase 1
While we don't predict any one tank will completely resist the pests, we do suspect the more balanced tanks to handle the presence of pests more effectively.  Presumably, the balanced biome means no single pest can dominate and outcompete the others to a point at which it dominates the resources and takes over the tank. 

The presence of microcrustaceans in some tanks does appear to be an effective defense against virulent outbreaks of diatoms and algae through phase 2. Can the introduction of pods eliminate an existing diatom bloom?  Should we ALWAYS introduce pods to a new aquarium early, before turning on the lights, as a means of preventing nasty outbreaks of pests?  Stay tuned for phase 3 where we introduce Algaebarn Ecopods to all of the test tanks. 

Tank #1 - Dry Rock, Dry Sand & 2 Cups of Established Live Sand

Test Tank #1 Phase 2 - Week 16
Test Tank #1 Phase 2 - Week 25

This tank was a "shared biome" tank in which we pulled 2 cups of sand directly from the display of a very mature aquarium here at BRS, "Steve's Tank" as we call it around here. While it scored fairly well with AquaBiomics in terms of biome balance, the presence of photosynthetic pests was undeniable, specifically explosive orange diatoms.

The good news is we finally saw evidence of microcrustaceans showing up after adding the pest slurry. While the diatoms bloomed heavily at first, once the microcrustaceans showed up, the diatoms slowed way down. After cleaning the tank manually on week 21, the diatoms seemed to go away but were replaced by chrysophytes.  

While borrowing sand from an established tank works for sharing biome, it also works for sharing photosynthetic pests which ultimately caused some pretty ugly outbreaks. Could we have prevented or reduced the severity of outbreaks by introducing copepods sooner in the process? 

When we consider the relatively decent results we had using dark-cured rubble rock as a means of "shared biome" placed in the back filtration chamber (where it doesn't receive light), the shared sand approach isn't what we would consider successful. The sand introduced a virulent strain of diatoms that could have been avoided using dark cured rock or bio-media. When one pest was resolved, another just took its place which happened in both phase 1 and phase 2. 

Tank #2 - Dry Rock, Dry Sand "Control Tank"

Test Tank #2 Phase 2 - Week 16
Test Tank #2 Phase 2 - Week 25

This was one of the most surprising tanks in that it produced the best biome balance score through phase 1.  After introducing the pest slurry we quickly saw an outbreak of chrysophytes which were then replaced with a nasty outbreak of those orange diatoms which persisted through the end of the test.  Yet another example of the microbial; pests battling each other to dominate the resources.  

In this case, the lack of any natural diatom predators like copepods was likely the reason we saw such a persistent diatom bloom. On the flip side, we never saw cyanobacteria, dinoflagellates, or hair algae in this tank throughout the entire experiment. Could it be the well-balanced biome and resulting biofilm that prevented those pests altogether?  Could we have introduced microcrustaceans to avoid nasty diatoms? 

Tank #3 - Gulf Rock

Test Tank #3 Phase 2 - Week 16
Test Tank #3 Phase 2 - Week 25

Arguably the most visually appealing tank of our experiment and most certainly the most natural biome introduction. The Gulf Rock is collected from the ocean and then shipped in water in order to retain the maximum amount of living organisms, including those beneficial microcrustaceans which showed up early in phase 1 and remained throughout the entirety of the experiment. 

While the tank didn't perform all that great during phase 1, it was one of the most capable tanks through phase 2 in terms of fending off most of the pests. While the balance score was the worst, the diversity scores were the best indicating the presence of many competing organisms which probably helped to overcome the variety of pests that popped up.

By week 25, chrysophytes were gone and only hair algae remained; the virulent orange diatoms never even showed up presumably because of the robust population of diatom predators (copepods). 

Tank #4 - Block of Established Marine Pure

Test Tank #4 Phase 2 - Week 16
Test Tank #4 Phase 2 - Week 25

The Marine Pure was established in the sump of our 900-gallon display tank and placed directly in the display of the test tank which obviously created some problems with photosynthetic pests through phase 1. We also noticed a healthy population of microcrustaceans including pods, worms, limpets, and snails which created a redundant layer of biome redundancy that seemed to actively help reduce or prevent the outbreak of pests. 

After the introduction of the pest slurry, we actually saw the algae slowly start to go away which was similar to what happened in the Gulf Rock tank. Could that diversity, pest or otherwise, be a benefit?

By the end of week 25, there were some traces of hair algae but ultimately the tank was free of diatoms, cyanobacteria, dinoflagellates, and chrysophytes meaning something was working.  

Tank #5 - Indonesian Live Rock

Test Tank #5 Phase 2 - Week 16
Test Tank #5 Phase 2 - Week 25

It was surprising to see how both of our natural live rock tanks performed poorly during phase 1 but unlike the Gulf Rock tank, the Indonesian Rock tank had a bit more trouble through phase 2.

Indonesian rock is different in that it is pulled from the ocean and then shipped damp, wrapped in wet newspaper. This method of shipping seems to reduce the sheer quantity of biome that comes in on the rock, at least compared to what we experienced with the Gulf Rock that is shipped in water. If not reduced, most certainly a different biome, whether that be because of the origin location or the shipping method. 

This tank pretty much experienced every pest at some point or another.  Out of phase 1, the rock was covered in golden algae and after the introduction of the pest slurry, the explosive diatom bloom took over and remained through the end of week 25. 

This certainly challenges the common idea of live rock being the most valuable source of biome in a reef aquarium. Even with the presence of microcrustaceans preying upon diatoms and algae, the outbreaks occurred. We suspect the population of diatom predators was simply not established enough or just not the right kind of microcrustaceans needed to curb this virulent diatom bloom. 

Tank #6 - Caribsea Ocean Direct Live Sand

Test Tank #6 Phase 2 - Week 16
Test Tank #6 Phase 2 - Week 25

At the end of phase 1, the Ocean Direct sand seemed to produce one of the best results visually and the introduction of biome was evident early on based on the DNA analysis scores from AquaBiomics. Even though this sand is collected from the ocean, there is no microcrustaceans meaning the tank lacked those helpful diatom predators. Through phase 2, it was obvious the tank wasn't prepared to handle the introduction of pests. 

It took 4 weeks for the explosive diatoms to show up but once they did, the minimal hair algae growing in the tank was quickly outcompeted. Upon cleaning the tank during week 21, the surfaces of the tank were stripped clean which seemed to open the door for not only the diatoms to come back with a vengeance but we also experienced a purple slime on the tops of the rocks, most likely cyanobacteria or dinoflagellates. 

Again, those orange diatoms outcompeted everything and we can't help but wonder how this tank would have performed if we introduced diatom predators first.  

Tank #7 - Aquaforest Method

Test Tank #7 Phase 2 - Week 16
Test Tank #7 Phase 2 - Week 25

The Aquaforest approach is unique in that we dosed AF Life Source throughout phase 1 of the test which is a type of naturally collected reef mud that is intended to introduce natural diversity. The mud created a dark mat on the sand bed which wasn't the most visually appealing but there was an obvious biome benefit evident in the AquaBiomics test results.  No Microcrustaceans were evident in this tank throughout the entire experiment meaning both Ocean Direct and AF Life Source are not bringing those organisms into the tank even though they are naturally collected. 

Interestingly enough, the Aquaforest approach produced almost identical results as the Ocean Direct tank. Both tanks were seeded with naturally collected substrates that wound up earning almost identical biome diversity and balance scores. Ultimately, both tanks had the same journey through phase 2 which started with some algae and chrysophytes followed by a persistent bloom of diatoms. 

While dosing mud seemed to create an unsightly appearance in the tank, the biome results were positive.  Just like the Ocean Direct tank, we are excited at the potential this approach may have. Could we simply mix the mud into a dry substrate (rather than dose it) to achieve the same diverse and balanced biome? Will the introduction of diatom predators help create biome redundancy and further resist photosynthetic pests?

Tank #8 - Live Coral "Insta Tank"

Test Tank #8 Phase 2 - Week 16
Test Tank #8 Phase 2 - Week 25

This has become a popular approach alongside the rise in sterile dry rock.  Introducing live coral into the tank is a "shared biome" approach where the coral and their mounts hold the seeded biome.

It was undeniable that this insta-tank produced a healthy biome through phase 1, complete with beneficial microcrustaceans and a particular coral pest, Red Planaria Flatworms. After the introduction of pests, the tank only grew a mild layer of cyanobacteria but the flatworm population kept increasing.  By week 19, the orange diatoms showed up but was nowhere near the severity we saw in other tanks.

The diatoms stuck around through the end of week 25 but were primarily confined to the sand bed which was unique. We suspect the presence of microcrustaceans helped to curb the diatoms. The absence of algae, dinos, and chrysophytes was a positive takeaway from this tank but the outbreak of diatoms supports the idea that when any one organism is allowed to take over, things don't go smoothly. The red flatworms grew exponentially in the tank and are known predators of pods, algae, and various other things that could have potentially competed with the diatoms.

Tank #9 - Dark Cured Rubble Rock

Test Tank #9 Phase 2 - Week 16
Test Tank #9 Phase 2 - Week 25

The dark-cured rubble rock produced the best results out of all 12 tanks throughout both phases. Not only did the tank look good through most of the test, but it was able to fend off the pests all on its own. Pests did show up, they just weren't severe and quickly resolved themselves. There were obvious signs of microcrustaceans early in phase 1 combined with a balanced and diverse biome coming out of phase 1.  

Why did the dark-cured rubble work so well?  The biome was successfully shared from an established tank without bringing photosynthetic pests into the tank which is a direct result of the dark curing process where the rock is kept alive in a container without light for 6-8 weeks or more. This allowed a balanced biome to establish during phase 1 alongside a redundant population of microorganisms. Upon introducing the pests in phase 2, the tank was able to retain its balance and handle small outbreaks of pests.

The natural evolution of this tank would be the introduction of clean-up critters and herbivorous fish to further boost the tank's resistance to photosynthetic pests. Biome balance and diversity success where no one pest is allowed to take over because natural predators exist which keep those pesky organisms in check. Best of all, the approach is attainable and easy for hobbyists to replicate. 

Tank #10 - Established Rock and Sand from BRS360

Test Tank #10 Phase 2 - Week 16
Test Tank #10 Phase 2 - Week 25

In this case, the rock and sand were pulled from the display of an existing tank and placed into the display of our test tank. It wound up being one of the top performers but still could not fend off hair algae and chrysophytes. 

Coming out of phase 1, the tank had some patches of serious hair algae growth that in a real-world scenario could probably have been addressed with clean-up crew inverts and herbivorous fish. Nonetheless, these pests didn't resolve themselves even with the presence of microcrustaceans.  Upon dosing the pests, the tank grew some bulbous chrysophytes alongside the hair-algae within the first 3 weeks. At week 19, a slight hint of the orange diatoms shows up but is gone inside of a week. 

After manual cleaning, the tank looks pretty good and ended phase 2 looking fairly clean with just some minor algae growth on the rocks and sand.  Something was working to keep the diatoms at bay and what other pests that did show up were kept in check. 

While the benefit of the shared biome and diversity from the donor tank was evident, the photosynthetic pests that popped up during phase 1 stuck around through most of the test. With that in mind, most hobbyists would agree that avoiding explosive diatoms is a win.  

Tank #11 - 100% Water from BRS160

Test Tank #11 Phase 2 - Week 16
Test Tank #11 Phase 2 - Week 25

Easily the worst performing tank, it's obvious this approach of using shared water isn't going to produce the best results. We suspect the reason is that using established water only limits the diversity of organisms that can be shared resulting in a less diverse and less balanced biome.

While phase 1 ended with the tank looking alright, with the introduction of the pest slurry it went downhill fast. It started out with chrysophytes which were replaced with diatoms by week 19. Even after a manual cleaning, the diatoms came right back.  A thick sheet of cyanobacteria showed up around week 23 which grew alongside diatoms and persisted through the end of the test.

Tank #12 - Real Reef Rock

Test Tank #12 Phase 2 - Week 16
Test Tank #12 Phase 2 - Week 25

Coming out of phase 1, the Real Reef rock looked great with the nice purple color on the rocks which help disguise mild outbreaks of photosynthetic pests.  Real Reef rock is cured in saltwater which carried diversity into the tank and it wound up testing really well with AquaBiomics through phase 1.  Unfortunately, the lack of predators and the presence of photosynthetic pests in phase 2 resulted in the worst-looking tank of all. 

Just 3 weeks after dosing the pest slurry the tank exploded with orange diatoms which stuck around throughout the entire test. There were no signs of cyano, dinos, algae, or chrysophytes but the diatoms were aggressive and even after cleaning, they grew right back. The moral of the story is we need to do our best to avoid the diatoms and introducing a diverse biome with microcrustaceans can really help to keep these pests at bay.