[Ninong]

Marine Depot, Radium 150w 20,000K HQI DE lamp

Note: Radium does not advertise a 20,000K rating for any of their "20,000K" lamps. They simply call them "blau," German for "blue."

[ChrisP]

Just ordered the Radium 20K from Marine Depot, thanks to your excellent (and unbelievably timely!) advice.

One more question. I was thinking about fitting some eggcrate to the top of my tank to keep fish from jumping (when I get a couple). Do you feel that this will have a significant effect on the lighting strength. Also - might a clan be possible with the Radium bulb, placed on rockwork about 8" beneath the bulb?

[Ninong]

Originally Posted by ChrisP

One more question. I was thinking about fitting some eggcrate to the top of my tank to keep fish from jumping (when I get a couple). Do you feel that this will have a significant effect on the lighting strength.

Yes, it will, especially with the light coming from a single metal halide source. It would make less difference with fluorescent tubes that extend across the full length of the tank because the light would be coming straight down evenly across the tank. With a single metal halide, even considering the reflector, a lot of the light is heading down at an angle.

I used eggcrate over my 120-gal tank but none of it was under the metal halide fixture. And the eggcrate over my tank was not resting on the tank itself. It was supported at a height equal to the height of the light fixture. My tank was jumper-proof because of my fairy wrasses. (See attached photos.)

Also - might a clan be possible with the Radium bulb, placed on rockwork about 8" beneath the bulb?

It might be possible. Again, don't attempt a crocea because they require the most light by far. Try a maxima and place it directly under the metal halide lamp.

[Ninong]

Another option that some hobbyists have employed for covering the top of their tanks is bird netting. I have seen that on top of some fairly large tanks. I think they sell it at home improvement stores, probably in the garden department. It's probably nylon and it's just a mesh (about 1/2" squares) with very fine "threads."

I'll see if I can find the pics that this one guy posted on another board. He made a frame for the bird netting so that he could simply lift up the entire frame for access to the tank. It looked like it probably had very little effect on the lighting.

Here is a photo of what that other guy did with bird netting.

[ChrisP]

Here's the "Bird Net Frame" top I've made. Chris

[ChrisP]

I put my Radium 150W, 20K DE bulb in today. WOW! Finally my corals are flourescing/"popping". It clearly provides actinic-like effects, yet, at least to the eye, seems far brighter than the 14K it replaced. I'm a very happy camper. Thanks so much for your advice, Ninong!

Now I have to figure out how to set the white balance on my camera. Photos of the tank look like blue dye was poured in.

[Ninong]

Originally Posted by ChrisP

I put my Radium 150W, 20K DE bulb in today. WOW! Finally my corals are flourescing/"popping". It clearly provides actinic-like effects, yet, at least to the eye, seems far brighter than the 14K it replaced. I'm a very happy camper. Thanks so much for your advice, Ninong!

Thanks for posting the feedback on the difference between your new Radium 150w 20,000K HQI DE lamp and your previous 14,000K lamp. That's the sort of comment that helps others who are trying to decide what to get. This seems like a perfect choice for your particular tank (24-gal) and your particular fixture. Now you don't have to worry about how you might be able to add actinic lamps to supplement your fixture that holds only a single 150w DE lamp.

You seem to be pleased with your purchase even though it was more expensive than some of the other choices. One thing we have to always keep in mind and that is that we ourselves have to be pleased with the appearance of the tank. It doesn't matter how good a particular lamp is or how much PAR it puts out if we can't stand the look of the tank. In this instance, the Radium 20,000K in the 150w size seems to have more PAR than any of the 14,000K or 20,000K lamps tested by Sanjay. The only drawback seems to be that the price is a little higher.

Now I have to figure out how to set the white balance on my camera. Photos of the tank look like blue dye was poured in.

You should post that question in the Photo Lab forum.

[ChrisP]

The extra $30 I spent on the Radium bulb (as compared with Ushio, Phoenix, Hamilton, etc.) was forgotten immediately as soon as I saw the result of spending the extra money. Truly, it would have been worth double that.