250 or 400 watts?

[canadawest]

With a tank only 18" deep, and factoring in a couple inches of substrate, you'll likely be fine with 250W MH. You'll save on both the initial cost, and cheaper to operate, and much cooler to run.

If you are going to go mostly SPS, Clams, or other light hungry animals, and will have adequate cooling, then the 400W is not much more expensive.

Mostly a judgement call, but I think you'd be fine with 250W.

[clintyiu]

Hello,

I will ordering a blueline ballast for my new DIY canopy but I cannot decide on the 250 or 400 watt.

It's for a new 46 gallon tank (18"x18"x40") with SPS (hopefully). The canopy will house 2-36 watt PC actinics and the MH bulb will be mounted on a track with a gizmo that will move it back and forth along the tank.

Does a 250W MH (Iwasaki or blueline) throw enough light for this tank?

TIA
Clint

[One_Divided]

I went for a 400w iwasaki on my 50gal and it was only about $20-$30 more then 250..

In the Aquarium and reef 2002 magazine there's a good article on the halide bulbs that conpares both iwasakis

[DJ88]

I run a 250 on my 33 with an 18" depth.. you should be fine with that.. I get fabulous growth. Take a peek in this forum you will see a growth thread of mine. I'll be adding a new pic shortly to this as the montipora in that thread has grown again..

If you do go for a 400W.. Be sure to acclimate(to the light) everything on the sand bed then slowly raise them up to where you want them.. If not you may harm them or shock them suddenly. I'd give it a week or so down low.. Unless the frags are from a shallow 400W tank.

[ 19 December 2001: Message edited by: DJ88 ]

[clintyiu]

Hmmm...

Still a pretty tough decision. The difference in energy cost is only $30 a year with a additional 15 for 400W replacement bulb. So it is not a cost issue.

Is 400w a more common wattage?

[reefburnaby]

Hi,

It is commonly accepted that PAR is most important factor for lighting. Unfortunately, some 400W MH can not produce as much PAR as Iwasaki 250W MV. So...its highly dependent on the bulb you use. If I went with a lighting system, I would go 250W MV or 250W HQI. These have the highest PAR per W ratio that I have seen published. Iwasaki makes a 400W MV too...but you might not like the colour.

Any who, be it 400W MH, 250W MV, 250W HQI...all of them should be fine for most SPS.

- Victor.

[maimz]

anyone ever tried the sunmaster metal halides..i know they are the best for hydroponics...although this doesnt holdmuch meaning over here..they do have an amazing blue/white spectrum product that might be worth checking out..they are the number 1 in PAR watts so i urge you guys to check them out..from what i know about hydroponics the 250w are a waste of time and money as you can have the 400w for peanuts more....this would allow you to have the light higher from the tank and spread the light out more...btw..anyone have a line on sheets of hammertone for a reflector?