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LED Planted Aquarium Lighting: Part 2

DJKronik57 — Thu, 15 Oct 2009 16:20:00 +0000

In the first part of the series on LED lighting in the planted aquarium, I discussed whether or not LED lighting would work for growing live freshwater plants, and if so, why hasn't anyone made a fixture you can buy yet that isn't $1,000+. Now if you're either brave and the DIY type or have some deep pockets and want to give LED lighting a try, but need that extra justification to give you a push, here are some quick pros and cons of LED lighting in the planted aquarium:

Pros

First, the pros, and there are lots of them. You'll find that most come with some caveats though.

The first one that jumps into many people's minds is their lower energy consumption. Most high powered LEDs (the sort you use for growing plants) only use 2-4 watts of electricity and pump out anywhere from 100 to 300 lumens (for comparison a 70 Watt metal halide bulb produces around 5000-6000 lumens). So depending on the size of the aquarium and the quality of LEDs that you buy, you could see a slight drop in power consumption. However, this drop is not huge, contrary to popular belief. If power saving is your main qualification, I'd lean more towards T5 fluorescents (these usually put out about 2000 lumens for a 24 watt bulb).

Another benefit of using LEDs is that they don't emit quite as much heat as high temperature metal halide lamps do. Again, there have been misconceptions about LEDs thinking that they don't create much heat at all. Regular low powered LED's don't really, but high output LEDs do. Substantial heat. So much that you need heat sinks and fans to keep them cool. Granted, they don't get quite as hot as metal halide lamps, but they require more robust cooling systems than any fluorescent fixtures. And heat is critical determinant to how long an LED lasts, which brings me to my next point.

LEDs last a long, long time if they are treated right. This is a huge benefit over fluorescent bulbs that dim or shift their spectrum and need to be replaced every 8-12 months. I just shelled out $70 for two new bulbs for my 2 x 96 Watt CF fixture and will need to do so every year. LEDs should last the life of your aquarium (or at least 50,000-100,00 hours) provided their temperatures are controlled. You see, the lifespan of an LED is directly linked to its operating temperature. The hotter they run, the sooner they burn out. This is why heat sinks and cooling fans are necessary.

Another big difference between bulb type lighting (fluorescent and metal halide) and LEDs is that LEDs do not require fancy reflectors. They emit all of their light in one direction via highly efficient internal reflectors, and therefore eliminate inefficiency due to light bouncing off the reflector and back into the bulb or off into the room instead of into the tank. If you are putting together your own DIY fixture, this means that buying a reflector isn't always necessary (depending on your LEDs) and can save on costs and space a bit.

LEDs are small, and produce a lot of light in a very small space. Only metal halides pack as much light in a small space. Try lighting a nano tank to levels that qualify as high light with a flourescent and you'll see why this is awesome. In order to be high output, fluorescent bulbs need length...and that won't work on a tiny tank (except spiral CF bulbs). You can't really put a 70W metal halide over a nano tank either, unless you're planning on boiling some water. This small space footprint also brings up another benefit of LEDs, although it is purely aesthetic.

LEDs produce that ever-illusive shimmer effect. You know, the glimmer in the water that sun casts that just looks so awesome. Until LEDs, only metal halides could do that, since they were the only other point-source (meaning all light is emitted from a small area) fixtures available to planted aquarium keepers. As stated before, metal halides don't really work over smaller tanks for obvious reasons. Now those of you with smaller tanks can bask in the shimmering glory as well!

Finally, LEDs can produce exactly the wavelength of light needed by plants. There are very specific wavelenghts that plants use for photosynthesis, and if you didn't care much about how the planted tank looked to the human eye, you could buy LEDs that only emitted these wavelenghts. Of course, that wouldn't look very pretty...or natural, since it would be only red and blue light. But the point is you can control the wavelengths present in your lighting, instead of a wide range produced by other types of lights.

Cons

There are a few cons to LED fixtures, the largest being cost. LEDs are just too expensive still to use for large aquariums and provide the light necessary for plant growth. At approximately $10 an LED, not including controllers and cooling systems, the costs quickly add up. It's easy to see how commercially produced fixtures like this one sell for $700-$1000. Eventually, the costs will come down as high output LEDs are put into more and more applications, but for now, we're stuck with paying for this new technology.

Another downside of LEDs is that they still produce a large amount of heat. They aren't the ideal solution for aquariums that are highly sensitive to heat, or in hot climates where keeping the tank cool can mean running a chiller or blasting the air conditioning. They don't quite reach the temperatures of metal halides though.

And finally, considering there are only a few large commercially produced LED fixtures available, if you want to light a smaller tank, or if you can't afford the large fixtures, you'll probably have to make your own using parts bought online. This requires soldering, wiring, and constructing a housing that can effectively cool the LEDs. It's no small undertaking, but it is possible and fairly straightforward.

Final verdict: If you have a small tank (too small for most fluorescent tubes and metal halides), some electrical DIY experience, and don't mind putting together a cooling system, a small LED fixture is probably your best option for high output lighting.

Planted Aquarium Mishaps

DJKronik57 — Mon, 27 Jul 2009 19:41:00 +0000

I'm sure we've all had our share of mishaps when it comes to keeping aquariums. Mixing glass, water, and electricity is a recipe for disaster. I thought this thread about aquarium mishaps was pretty interesting, and I'll share my biggest mishaps to date.

First of all, I've come to the realization that heaters, submersible or not, are probably the most dangerous piece of equipment in an aquarium. They're often glass, and sometimes non-submersible. Combined with electricity...well, it's a bad mixture. Most of the time it's as simple as forgetting to turn the heater off when you do a water change. The heater turns on, heats up much to fast (since it's supposed to be "cooled" by water) and either burns up or, even worse, when you refill the tank, cracks the glass when it comes into contact with water again. Some heaters are designed with an auto-off switch to prevent this. I've killed at least two heaters this way. Luckily, it's fairly easy to notice, given the smoke, steam, and possible fireworks. One of mine just burned up before I raised the water back up, but the other shattered when it contacted the water. Luckily, my fish (and me!) got away without any injuries. I've vowed to never buy cheap heaters again, and always, always use a GFCI outlet or power strip (which should probably added to the 10 Items a Planted Aquarium Keeper Can't Live Without list).

Another mishap occurred when setting up my pressurized CO2 system. I bought a regulator with a bubble counter and filled it with water. I screwed the cap on tight and everything was great for about 2 weeks. Then I noticed that my water level was dropping more than normal between water changes, and the bubble counter was often full of water. It had an integrated check valve, so I wasn't worried about my regulator being damaged. However, I then realized that the floor of the stand underneath the tank was literally mushy and soaked. I examined the CO2 setup for leaks and realized that on the back side of the bubble counter, hidden out of view, was a nice big crack that must have been slowly spreading since I screwed the cap on. Each night, when the CO2 went off, water would siphon back and drip out through the crack. My stand is pretty funky inside now, and the particle board that got wet is deformed and expanded. Let's just say the floor inside isn't exactly flat anymore. I ordered another bubble counter and was extra careful screwing it in.

A few more minor mishaps:

I've accidentally overfilled my tank while doing a water change and watching TV at the same time. I suddenly had a waterfall in my living room! Don't multitask while filling your aquarium back up.
I've accidentally run my Eheim filter overnight with a kinked hose. Woke up wondering what the funny burning rubber/plastic smell was, till I realized it was my fish tank. The Eheim took it like a champ though, and still works fine.

I count myself lucky that I've avoided most major mishaps (no cracked tanks, major water damage, etc).

What about you? What planted aquarium mishaps have you had?

Earth Day and Aquariums

Fish Fan — Wed, 22 Apr 2009 21:44:00 +0000

Since its Earth Day, try to keep in mind how your aquarium impacts your environmental footprint. Here are some tips to keep your green without turning it green.

Use aquarium light timers
- You will save electricity and maintenance headaches if you use light timers to only run your lights for max 8 hours a day.
Stay away from Chemicals if possible
- It is always better to use natural remedies to problems with your tanks rather than using chemicals.
Buy tank raised livestock
- Buying tank raised livestock keeps our oceans stocked and curbs the threat of poaching and cyanide fishing.