October 1, 2006
Seagrass tanks are starting to become trendy and I am interested in trying something a little different from my other marine setups. I have just recently started researching planted aquariums. I have virtually no experience with saltwater plants and very limited experience with a few hardy freshwater plants, so this will be a learning experience for me.
I figure that the experience that I gain during this contest might translate into a neat looking seagrass refugium someday (a bit different than the more typical ball of Chaeto). Also, Iím currently in need of a decent quarantine tank (as I plan to replace my Yellow Clown Goby); and this tank should fit that need well.
My planned custom setup is very close to the stock contest requirements (with the exception of using daylight/daylight spectrum bulbs versus daylight/actinic, and using two alternating powerheads versus one that is constantly on). While these modifications are relatively minor, I feel that both of them will be positive additions to my little seagrass lagoon.
I plan on performing a maintenance routine that is similar to my other reef tanks (utilizing water changes to: balance water chemistry, supplement beneficial elements that were consumed, and dilute unwanted/excess elements). However, unlike my reef tanks, I will pay particular attention so that the tankís nutrient levels are not entirely depleted (possibly testing the seagrass refugium idea by using water changed out from my 40gal display).
I plan on providing a hospitable (but not deep) substrate. In addition, since I hope to avoid adding additional fertilizer, I will likely encourage NO3 (nitrate) production, especially as the grass becomes more established. This would be a 180į change from trying to reduce the production of NO3 in my other reef tanks. However, the growth of the seagrass will likely be limited more by CO2 (carbon dioxide) and light.
Since increasing CO2 lowers pH, I might not supplement CO2 (as managing pH would likely become more difficult). However, because the grasses will likely consume CO2 faster than it will be naturally replenished, I am going to leave this option open.
From what I have read, the 20Ē (40W) Current compact fluorescent fixture should be adequate to keep most varieties of seagrass in a standard 10-gallon tank. I will replace the standard (SmartPaq Daylight 10000ļK/Actinic 460nm 40W) bulb with a SunPaq Dual Daylight 6700įK/10000įK 40W bulb to provide a more suitable light spectrum for the seagrass.
In order to provide enough room for seagrass roots and rhizomes (often located in less oxygenated levels of the substrate), deep sand beds are typically recommended. However, by keeping seagrass with relatively shorter roots, I am hoping that this will be unnecessary (as I plan to keep the sand bed closer to 2Ē). Since I also hope to avoid adding additional fertilizer, I have decided to amend the Nature's Ocean Bio-Activ Live Aragonite Reef Sand (0.5 - 1.7 mm Diameter Grain Size) with Refugium Mineral Mud.
I plan on using a Penguin BIO-Wheel 150 HOB filter for filtration and surface flow. I also purchased 3lbs of cured live rock from a LFS in the area. Thatís not a lot of rock (just a third of a pound per gallon), but I will be keeping a relatively light bio-load. My thought is that the grasses will consume enough nitrates that I can start utilizing more aerobic bio-filtration (possibly from installing the bio-wheel and/or adding bio-balls to the HOB filter). I donít currently plan on using a skimmer; however, this could change in order to: assist with gas exchange, increase O2 (oxygen), correct pH problems, reduce dissolved organics, and/or slow NO3 production.
Additional water flow
My research indicated that seagrasses prefer high flow. Two Maxi-Jet 600 powerheads (160gph each) alternating by means of a Natural Wave Timer] will supplement the HOB filterís flow (bringing the total maximum flow to 310gph at any one time). Although the wave action is mainly for aesthetics, the motion might possibly assist the plants in utilizing CO2, O2, and other elements. Iím hoping that the Clown Goby, that I plan to keep, doesnít mind the flow (they are known to like SPS, which requires high flow, so Iím hoping that it will be fine).
I will be using a 25W Visi-Therm Stealth Heater. I would prefer to keep the temperature between 75į and 78į, but Iím guessing that my lights and pumps will end up dictating the final temperature setting. I usually set my heater to 2į or 3į lower than the tankís peak temperature (during the light cycle). I will likely keep an open top to encourage evaporation for cooling and gas exchange.
At 20Ēx10Ēx12Ē, the standard AGA 10-gallon tankís height restricts the depth of the sand bed, as well as the height of the plant and coral species. However, it should still make an excellent test bed for keeping Star grass. Plus, a 10-gallon tank is a reasonable size to mimic a potential star grass refugium.
Star grass (Halophila engelmannii): This species does not send roots as deep as some other varieties, nor does is grow as tall. I think it looks good too.
A Yellow Clown Goby (Gobiodon okinawae): This fish will probably be moved to my 40 gallon breeder after the contest.
I plan to stick with Blastomussa merleti growing on the Live Rock.
A shrimp, Hermit crabs, snails, feather dusters, and hitchhiker starfish will eventually find a home in my lagoon.