Lighting Question

[trockafella]

In an 18" deep tank, would a 150 hqi with a really good reflector (like a lumen max) be capable of growing SPS on the bottom or would you need a 250 for that..? Thanks

[BowieReefer84]

In an 18" deep tank, would a 150 hqi with a really good reflector (like a lumen max) be capable of growing SPS on the bottom or would you need a 250 for that..? Thanks

I'm not sure with other kelvins, but with a 14k-20k I would say no. If you are using a 10k and actinic supplementation I would say maybe (I do not have any experience with this).

 

I base this off having a 150watt phoenix over an 18" tank. I had everything in the upper half. Not to say things won't "open up" down there. I just didn't see any growth on what I had at/near the bottom....

 

I am sure others have more experience will chime in.

 

EDIT: My reflector may not be as good either . . . fwiw.

Edited September 20, 2010 by BowieReefer84

[CHUBAKAH]

At 18" I think your fine with 150 watts. Lumen max's are rated to 30"

[bluefunelement]

I have a 150w DE PFO reflector with 14k Phoenix and was getting up to great PAR on the bottom.. too much for some LPS and softies in the middle bottom but fine for lower light SPS such as Monti Digi

I would say if you can get the groups PAR meter and confirm you have >100PAR near the bottom then you have some choices.

[Coral Hind]

I had dual 150w HQI's over my 75g for years and had no problems growing SPS at the bottom as long as I didn't try anything with a kelvin rating over 14k. With the 20k it was fine for about two months then the corals started to die underneath as the bulbs aged. Of course keeping the water clear with carbon or UV would help with light penetration.

[trockafella]

So a Phoenix 14K in a lumen max with a good ballast would be sufficient.? I also would think on an 18" tall tank with sand, it wouldnt even really be 18" from the waters surface to the sand bed.. Thanks for the answers..

[BowieReefer84]

Yea, the reflector you mentioned will be good. My opinion was based on another reflector. The 14k Phoenix color is great too IMO. I like the blue.

[trockafella]

Thanks for the answers..!!