I began using Chaetomorpha (pronounced “kay-toe-morf-a”) macro algae (Chaetomorpha spiralis) today for nutrient exporting as I am taking a new approach and attacking my Nitrate issue from multiple fronts which I have blamed for driving my Algae issue. I have already went bare-bottom, reduced volume of live rock, increased and improved flow, implemented ZEOvit system after trying Vodka dosing, reduced feeding after selecting the best food to use with minimal impact on nutrients, and upgraded skimmer.

I bought and installed a Current PowerBrite 10,000K Daylight LED Lighting System brick in the middle chamber where I placed a handful of chaeto. I chose chaeto over caulerpa as it is less likely get sucked into the pumps or spread throughout the sump through sexual reproduction. The downside it is a slow grower and traps detritus. I will need to be careful as it grows in a ball with outer portions receiving light with an increased likelihood the portion in middle dying off and then releasing the nutrients back into the water column. To help alleviate this, I will rotate the chaeto weeky and export extra as needed.

I will ensure I follow a good photo period regime to allow for proper photosynthesis process and respiration during dark period. I have read to maintain a photo period of 16 hours on followed by 8 hours off so not to stimulate reproduction cues for the algae usually triggered by shortening of photo period. Some argue it does not matter and run their refugium’s lights 24/7. So I can take advantage of the pH buffer benefit, I will have chaeto photo period alternate with my display tank photo period.

The Goal

• Nitrates below 4.4 ppm using LaMotte Test Kit
• Phosphates below 0.03 ppm using Low Phosphate Hanna Meter
• Improved SPS Coral Health
• No negative impacts on system

Hypothesis

Chaetomorpha absorbs nitrates and phosphates from the water column as its natural biological process which then can be exported by removing a portion of the Chaetomorpha on a regular cycle thus reducing overall free form nitrates and phosphates.

Observations & Notes

2009-12-02: Removed some of the Chaeto ball as appears I have had some growth. I expected more growth but believe I am not because my nutrients are finally limiting. I have not needed to scrape the glass in a week and it is still clear, bacterial bloom seems to be non existent, algae near undetectable, and coral health has been improving.

Nitrates still tested at 17.6 ppm and Phosphates at 0.03 ppm on Sunday but feel still elevated as the bacteria and algae have been dying and collecting in piles on the bare-bottom requiring me to siphon out a couple times last week. This has stopped as not much more left so I expect to finally see an additional decline in detectable nutrient numbers when I test this weekend.

2009-12-05: Nitrates tested at 17.6 ppm and Phosphates at 0.06 ppm. Disappointed as I expected to see a positive impact by now.

2010-01-03: I am not seeing much growth from the Chaeto even though Nitrates still at 17.6 ppm and Phosphates 0.03 ppm. I am believing the lighting is the issue as should be providing a light in the range of 2300K to 9600K spiral compact fluorescent bulb at 26w. Will need to explore purchasing a clip on fixture and bulb.

Conclusions

Experiment still in progress.

DISCLAIMER: Your results may very as each system is very different from another. For my tank parameters and environment, this was my observations and conclusion. This was not a controlled experiment so there is a potential for a very large margin of error.

References

Borneman, Eric. “Mything the Point: Part Two.” Reefkeeping. December 2003. http://www.reefkeeping.com/issues/2003-12/eb/index.php. Accessed 17 November 2009.

“Chaetomorpha.” Wikipedia. 12 October 2009. Wikimedia Foundation, Inc. http://www.liu.edu/cwis/cwp/library/workshop/citmla.htm. Accessed 17 November 2009.

Riddle, Dana. “A Different Look at Lighting: Effects of Prolonged Photoperiod, Spectral Quality, and Light Dosage.” Advanced Aquarist’s Online Magazine. May 20009. Reefs.org Publications. http://www.advancedaquarist.com/2009/5/aafeature. Accessed on 26 November 2009.

Schwartz, Gene. “A Warning Sign of Impending Caulerpa Sporulation.” Reefkeeping. May 2004. http://www.reefkeeping.com/issues/2004-05/nftt/index.php. Accessed 17 November 2009.

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