Dabbling

WHAT IS THE DIFF. BETWEEN T5 AND METAL HALIDE LIGHTS? WHAT WOULD BE BETTER FOR A REEF AQUARIUM?

T5 = Fluorescent lighting with bulbs that are 5/8" diameter. These bulbs are smaller than standard T8 and T12 fluorescent bulbs. Therefore more bulbs can be fit into the same space as the larger diameter bulbs.

The efficiency of T5 bulbs is largely dependent upon the quality of the reflectors used. The cheaper, less expensive T5 fixtures use a single flat piece of aluminum above the bulbs to reflect the light downward. The better reflectors are up to 300% more effective. They are single reflectors above each individual bulb. The shape of these better reflectors are parabolic in shape and highly polished. The parabolic shape takes the light that shines out of the top of the T5 bulb and 'bends' it around the bulb and down into the tank. The cheaper flat piece of aluminum just takes the light emitted from the top of the T5 bulb and reflects it straight down, basically back into the bulb itself, rendering that light useless, for the most part.

T5 lighting is also a linear source of light. Therefore the light is emitted from the length of the fluorescent tube and more evenly distributed within the aquarium.

The heat generated by T5 lighting is much less than the heat generated by MH lighting. It is still important to keep the T5 bulbs cool by running a fan across the bulbs. Keeping the bulbs cool will help to extend the life of the bulbs and lengthen the replacement period.

T5 lighting is adequate for any of the marine animals we keep in our tanks. The downside to T5's is the intensity of the light at depths greater than approx. 22"-24". For taller tanks it is either recommended to use MH lighting or strategic placement of your corals. Arranging higher light demanding corals in the upper 1/2 of the tank and the lower light demanding corals on the lower 1/2 would permit you to use T5 lights on tanks taller than 24". Just be realistic with your expectations and use the above strategy to compensate for the T5's shortcomings.

MH = Metal Halide lighting. This is a very intense, point source of light. Comparing it to a T5 bulb trying to create an apples to apples type of comparison, you'd either have to stretch out the MH light to emulate a T5 bulb, or shorten the T5 bulb so that all the light would come from a single point. The MH lighting being point source, decreases in intensity as you move from left or right from the center point directly below the bulb.

MH bulbs typically lose their efficiency in 7-9 months depending upon how many hours a day you run the bulb. Heat output from a MH bulb can easily burn a person, badly. Therefore it can also burn or 'bleach' a coral if you are changing from a less intense source of light to MH without acclimating the new MH lights. In other words, if you want to change from power compacts, T5's, dare I say incandescent, etc., it is important to either raise the height of the MH fixture/pendant and/or shorten the photoperiod the MH light is on. Strategically increasing the photoperiod over the course of a couple of weeks and/or lowering the height of the fixture should acclimate your corals and inverts to the new, more intense light.

MH bulbs are designed with varying wattages to allow for different tank designs. They primarily come in wattages for aquariums in 70w, 150w, 175w, 250w, 400w and 1000w. Bulb type also varies between SE (Single Ended) and DE (Double Ended) mounting styles. The last varying factor in MH bulbs is the kelvin rating they emit. The lower the kelvin rating 5000K, 6500K are more in the yellow/red spectrum, and bring out those colors in the animals in our tanks. The middle range of the spectrum is in the 10000K, 12000K, and 14000K range. These bulbs are more of the crisp white spectrum. Then we've got the 15000K, 20000K and even some 22000K bulbs on the market. These are the bulbs that bring out the blues in our corals.

Many people like to use a mixture of MH bulbs in the 10K-14K (same as the above kelvin ratings eliminating the three zeroes) to bring out the crisp white, or daylight spectrum as if the sun were high in the sky, with T5 bulbs in the 20K range. Using a combination of bulbs like this makes it very easy to simulate an effective sunrise/daylight/sunset lighting period.

MH bulbs produce a lot of heat and can easily cause aquarium temperatures to rise to unhealthy levels. Therefore it is important to take into consideration the ambient room temperature where the tank is located. If you run A/C in that room during the warm/hot months and the room temperature remains in the 70-75 degree range, you might be ok. If you don't run a room/house A/C while you're not home, and the room your tank is in can rise to the 80-85 degree range, you may need to get yourself an aquarium chiller. This can also be true for T5's, but more likely to happen with MH bulbs.

Great source for reef lighting is Saltwater Critters. See the links below.

Nano Reef Aquarium

There is a new growing popularity in the reef keeping hobby called Nano Reefs. As the name implies, a nano reef is a reef aquarium on a small scale; 2.5 to 29 gallons. The price of a nano reef is also on a small scale, from the tank itself, the lighting, and it takes less live rock and corals to make a very dramatic reef display.

It was often thought that the bigger the aquarium the easier it would be to keep the water parameters stable. You could not keep corals alive without a massive trickle filter, large efficient protein skimmer, and powerful metal halide lighting lights. The bigger the aquarium the more gadgets you could add to make the water quality pristine, from ozone generators, redox meters, ph controllers, and calcium reactors. You had to be a marine biologist and a chemist to maintain a coral reef aquarium. The nano reef aquarium would seem to go against all these principles. Can we really keep corals alive in a 10 gallon aquarium with no sump filter or a protein skimmer?

What has been learned through the years more than anything is, most of the biological filtration occurs in the live rock and live sand. Lighting has also played a role in enabling the reef aquarium to become smaller with the advent of power compact fluorescent and the smaller HQI metal halide lamps. Having invertebrates that sift through and clean the live sand and live rocks ads to the ecological balance of the tank. Most of the trace elements are replaced through a strict regiments of 5% weekly water changes. There is yet to be a salt water mix that has adequate calcium and strontium levels for good coral growth and these elements should be maintained separately.

The best products to maintain calcium, strontium and other trace elements are made from aragonite, such as AragaMilk from CaribSea. So what is aragonite? Aragonite is fossilized coralline algae that has extracted minerals from the ocean to grow. Grinding aragonite into a fine powder and adding water creates a milky substance that precipitates quickly adding these minerals to the water naturally. Add a few drops to top off water to maintain calcium levels at 450 ppm. You will be amazed at the growth rate of SPS corals. Yes I did say SPS corals that can be easily maintained in a nano reef aquarium.

Fish For The Nano Reef Aquarium

Fish are a great addition to a nano reef, but you must take extra care of you nano. You will have to be sure to keep up with your water changes, because a small body of water can collect nitrates quickly. The following fish are nano reef safe: anthius, true and false percula, banggai cardinals, pajama cardinals, royal grammas, fire fish, clown gobies, pseudochromis, basslets, and most damsels. While you are not limited to just those fish, these are hardy and good for beginners. Keep the number small from 1 to 5 fish depending on the nano aquarium size.

Cleanup Crews For The Nano

A good cleanup crew will keep your nano reef running smooth, and free from algae, detritus, and other unwanted wastes. Commonly kept cleanup crew critters are red leg hermits, red tip hermits, sand sifter starfish, sand sifter gobies, turbo snails, and astrea snails.

Corals For the Nano Reef

There are may corals that are compatible with the nano tank. Soft corals would include zooanthids, zenias, star polops, and mushroom anemonies. Lps corals would include Fox Coral and Blastomusa. SPS corals do well with metal halide lighting. Acroporas and montiporas are the easiest to grow in a 24-29 gallon nano aquarium. SPS coral frags are the way to go in a nano reef. They are much cheaper and easier to ship. The benefits of buying corals online is the greater variety that cannot be found at your local pet store. Buying several items from the same seller can reduce shipping costs. Simply use some Marineland's Hold Fast, which is a two part epoxy similar to plumbers epoxy, to glue the coral frag to a live rock. Be sure to give them plenty of space for growth.

For more information visit reefkeepingfever.com

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