Lighting for 300g

[berzer]

I thought I had figured out the lighting but i keep waffling back and forth about how much lighting is enough.

I have a 300g (8' x 2' x 30") tank.

I plan to light it with MH as I already have 2 250W MH bulbs.

Would a 400w bulb in the middle with the 2 250W on the sides, work fine and allow me to grow some fairly high light plants or would 3 250w do the same. I am not looking to go with four bulbs as I will be planting the sides fairly low light tolerant and one corner will get a bit of sun for two or three hours.

[Jamie]

First off, I've never used metal halides...I chose power compacts, but I did look into them and know a little bit. In your case with a tank that is 30 inches deep, I'd say halide is the preffered method of lighting. One thing I know about the halides is that they are more of a "spot" type of light. So considering how long your tank is.... How high will you be able to raise the bulbs above the water? Also consideration should be given to cooling them in some way...the halides are gonna give off a lot of heat and will definately affect the water temp to different extremes depending on how close to the water they are. As far as using the 400 watt bulb in the middle, if it were me (I'm no expert, just sharing an opinion) I'd go with two more 250's and have all four spread out evenly accross the tank, and maybe set the tank up with an open top. In my experience, uneven lighting equals uneven growth of plants.

[orgetorix]

I have the same tank and I use PC lighting. I got 6x96W from AH supply and they are great. I can grown some of the higher light plants with no apparent problems. I am using flourite as a substrate and CO2, but nothing seems to be growing up instead of outwards (like glosso would tend to do).

[berzer]

Originally posted by orgetorix
I have the same tank and I use PC lighting. I got 6x96W from AH supply and they are great. I can grown some of the higher light plants with no apparent problems. I am using flourite as a substrate and CO2, but nothing seems to be growing up instead of outwards (like glosso would tend to do).

So 750W of lighting with MH would probably be enough if I can get the light spread out across the tank fairly decently?

I notice that Amano in most of his 8 ft tanks in Nature Aquarium World Vol 1 only has 240-320 W anyways and his tanks are beautiful and seem to flourishing albeit using some plants that I wouldn't exactly consider high light.

Some of the newer reflectors for halides claim to allow you to use only 2 bulbs over a 6 ft tank. So 3 over an 8 ft tank would work just fine, wouldn't it???