The Biome Cycle experiment was based on twelve individual Red Sea Reefer 170 aquariums that we set up side by side in order to take a closer look at the cycling process and how that ultimately affects the resulting microbiome. Each tank was set up using a slightly different approach to cycling that ranged from sterile dry rock and live rock to sharing biome and media from existing aquariums.  

Tank #1
Tank #2
Tank #3
Tank #4
Tank #5

Tank #6
Tank #7
Tank #7
Tank #9
Tank #10
Tank #11
Tank #12


Evaluating Biome Health

The goal was to compare the results in each tank and hopefully gain insight into which methods are the most effective for creating a well-balanced microbiome. In order to do that, we established five different tests or criteria that we used to gauge the health of each of the various resulting biomes.

After all, what does a healthy microbiome look like?  We cannot physically see it so the signs or indicators are more complex than a simple observation. 

Biome Diversity

We used on Aquabiomics Environmental DNA diversity score which measures how many different organisms make up the microbiome in that particular tank. The tests are performed in the Aquabiomic lab and require water samples to be mailed to the lab directly.  All of the results will be shared throughout this BRStv Investigates series.  

While most of us believe diversity to be a sign of a healthy aquarium, we found that isn't always the case and only partially true, especially in new aquariums where there is an opportunity for pesky organisms (included in that diversity) to thrive. 

Biome Balance

Using the same Aquabiomics Environmental DNA testing, the Biome Balance score provides us with a measure of the good vs. bad in the aquarium and how they compare to each other. The scores are compared against a database of existing aquariums, taking those average scores to create a standard of what a balanced biome looks like. 

Visual Results under LPS Lighting (75 -150 PAR)

At the end of the day, we want our tanks to look good. After establishing the tanks without any light, we turned on the Neptune Systems SKY LEDs to provide a level of light and spectrum appropriate for LPS corals for another 6 weeks. We observed the photosynthetic pests that showed up and examined how these visual results correlated to the DNA testing.

Visual Results under SPS Lighting (200 - 350 PAR)

After the LPS lighting, we doubled the light output to hit the PAR range appropriate for SPS and found that a completely different set of photosynthetic pests showed up. These pests also showed up faster which was interesting to see and might tell us more about how the various approaches to cycling may work better in lower or higher light conditions.  

Introduction of Pests

Perhaps the most exciting test was our final test of introducing a myriad of pests we collected throughout the office. We created a "pest slurry" and dosed each of the 12 tanks twice and then proceed to see how each tank held up to these introduced pests. Only four tanks were able to withstand the introduction of these pests and we found some interesting shared characteristics that are common in well-established aquariums.

Knowing which approach worked combined with the DNA tracking of the results can help us develop more successful methods and reduce the severity of pests during the initial maturation of a saltwater aquarium. Stay tuned with BRStv as we uncover these methods and share even more exciting discoveries from our Biome Cycle experiment.