Metal Halide for 55g

[Cheese]

I'm looking at getting a 48" metal halide for my planted Freshwater tank, and was wondering if anyone could help me with some advice on what I should be looking for...?

I do have Flourite as well as Excel. My co2 is running, but not very strong.

[jvision]

If you're upgrading to MH, you'll love the rippled effect it creates with surface movement! However, because MH is so intense, you will need to keep CO2 and ferts in balance; otherwise, you'll have a constant battle with algae.

If I had MH, I would make sure that I had the tank close to 90% planted with fast-growing plants to start. These will help keep the algae at bay. When the other plants get established (ie Crypts, larger swords, etc.) then I'd start to take out the stem/fast plants. If you do this, you can keep a fairly high fishload from day 1, and you will win the algae battle. If you plant the tank only 50% (I mean of total bottom surface), and only with plants you like, you will have algae... I am speaking from experience (even in the last month! Yes, even the experienced try to cheat ).

[werner]

I have a 2x 54wT5HO + 2x 150W MH combination on my 66gal planted tank. I run the T5's for 10 hrs and just do a 5hr burst with the MHs in the middle. I love the ripple effect and the plants pearl like crazy when it's going. The fish get some kind of O2 high and swim around like crazy too. The tank is very heavily planted and has pressurized CO2 (on demand via a pH controller).

I recently increased the MH duration, and am now getting a bit of hair algae growing. It's not out of control, but probably would be if they were on the whole day.

If you're going to go with really strong lighting, you really need to have pressurized CO2 and some experience with balancing your fert regime (NPK + iron + traces). It's like you're going to be driving a race car at a very high speed- you need a lot of precision tuning, performance quality parts, and plenty of driving experience. If any one of these is missing or gets out of whack, you're gonna crash big time. Nutrient deficiencies can appear in a very short time when there's a high rate of growth.

If you do want to go with MH, I like the Giesemann Tropic bulbs- nice sunny color, with a good output spectrum. You may also want to consider T5HOs or a combination fixture.

[byte]

I'm looking at getting a 48" metal halide for my planted Freshwater tank, and was wondering if anyone could help me with some advice on what I should be looking for...?

I do have Flourite as well as Excel. My co2 is running, but not very strong.

The wattage of the light(s) would be something I would look at. One metal halide (175 watt) light on a 55 gallon tank is about 3 watts per gallon (WPG). The higher the WPG, more C02 and fertilizers are need to keep things in balance to keep algae away. Here is a good site to explain the basics.

http://www.aquatic-eden.com/2006/10/top-3-...ng-planted.html

http://badmanstropicalfish.com/basics/basics_lighting.html

Planted freshwater tanks like a different color of light than saltwater tanks. Look for bulbs in the 6000 Kelvins to 9500 Kelvins (Color temperature, measured in Kelvins). Saltwater lights will often be a mix of a 10000K and 20000K (Actinic-blue). The 10000K lights will grow plants, but the 20000K blue lights will not do anything for the plants.

http://www.aquatic-eden.com/2007/12/unders...m-aquarium.html

I hope that helps