Reef Tank: Zeovit Notes

After a month of running zeovit filtration and supplements in my tank, I can finally remove myself from their exceptional marketing photos and take a look at what benefit it had provided for my tank. Given that my system and corals are still very young, its hard to draw any conclusive evidence. Further complicating the matter is that my tank has been quite healthy and algae-free since inception, and maintains a very low bioload (still only one fish). That said, I've noticed some nice coloration from all SPS species, especially my birdsnest which has taken a very bright pink coloration. Good polyp extension all around.



One thing the good people selling zeovit systems will impress upon you is that a special reactor is useful for running the filtration media. Giving the rocks a shake every day loosens the mulm that collects within the media, letting it drift into the system and feed the corals. I've found that for smaller tanks, running this media within a simple hang on filter, the Hagen Aquaclear, works just as well. This filter has a nice media basket with convenient handles at the top above the water surface. You can easily remove the top and give these a good shake to release a great cloud of organic filth for your corals to feast upon.

I've found the Aquaclear to be a great all-purpose filter. Currently I have a bag of activated carbon and a bag of liverock rubble running, with the rest of the space filled with approximately 1/3 liter of zeovit medium.

Reef Tank: More Testing

Here is a graph I generated showing the process of the nitrogen cycle in my tank to date. Note that the x axis is not to any particular scale as I don't test at regular intervals. Still, it shows all tests going in the right direction, towards 0.



Today I got another set of tests for the reef aquarium. Once corals have been added to the tank, it is important to keep levels of calcium high in the water so that they can create their skeletons. It is also important to keep the carbonate hardness of the water level (also known as alkalinity) high to make this calcium accessible to the corals and buffer against pH swings. The third test measures phosphates, which form from animal waste and precipitate calcium, making it unavailable to be used. Phosphates can also serve as fertilizer for algae growth. To summarize, I am looking for calcium levels between 400 and 500ppm, KH at 140 to 215ppm, and no signs of phosphate.

Todays Parameters:
Temperature: 81F
Specific Gravity: 1.026
pH: 8.0
Ammonia: 0ppm
Nitrite: 0ppm
Nitrate: 20ppm
Phosphate: 0ppm
Calcium: 480ppm
KH: 179ppm

I must say I'm surprised at how well everything has gone so far. The water levels above, aside from a slightly low pH, could probably sustain coral growth quite well. With ammonia and nitrite undetectable, the tank is ready to be populated. I am going to hold off at least another week before stocking, while I finalize the list of corals and fish I want to keep in my tank. I also need to upgrade my lighting fixture to metal halide before I can order any coral. Another week or two with the snails and hermits should help the tank to slowly prepare itself for these additions.

Chemistry: The Nitrogen Cycle

As mentioned previously, my reef tank is currently going through a startup phase in which the nitrogen cycle becomes established. As there isn't much for me to do until this phase completes itself, I decided to dig a little deeper on the chemistry of this cycle and how it specifically relates to reef aquaria.

Fortunately for those of us who spent too much time goofing around in high school chemistry, there are a number of talented professionals contributing to the knowledge base. Of particular note is Randy Holmes-Farley, a chemist at Genzyme (which just so happens to be down the street from where I work). He writes articles for several online reef aquaria journals, and this morning I enjoyed reading two on the nitrogen cycle: Nitrite and the Reef Aquarium and Nitrate in the Reef Aquarium.

Of specific interest in these articles were a few points that differ in marine aquaria from freshwater systems, and that also defy what is passed along in forums as conventional wisdom. For one thing, it appears that in saltwater systems nitrites are not considered highly toxic unlike in freshwater tanks where they are considered as deadly as ammonia. Randy also lists out proven methods of eliminating nitrates in the reef tank, which though also not considered highly toxic, can be contributors to nuisance algae. Both articles are a great read for those looking to get an introduction to these steps in the nitrogen cycle.