kelvin recommendations

[diabeetus]

i am looking to upgrade my lighting from t5's to a t5ho MH combo. i found a fixture (combo light) that im interested in and there is a drop down menu on the order page that lets you upgrade bulbs, fans, and ballasts before you order. the ballast and fan thing i can deal with later, but it comes stock with a 65k 175w MH mogul base bulb. my question is, will 65k be sufficient for a mh fixture? also, the lower the kelvin, the more growth? or is that wrong?

thanks,

Corey

[Robb in Austin]

I think a 6.5K light will be _very_ yellow looking in a tank. I'd go with a 10K or 14K lamp with that one. I think you are correct on K to growth ratio, but am not 100%.

[diabeetus]

cool, thanks. i forgot about the color being so yellow with a lower K. i think i am going to upgrade the bulb to 14k anyway, but i was just wondering if 65k would prevent me from keeping certain things.

[Robb in Austin]

I don't think it will prevent you from keeping anything, it just might not be nice to look at.

[diabeetus]

true. cool!! thanks, Robb!

[JamesL]

I believe 10K's are too yellow for most people, so I would hate to see what 6.5K's are! I personally have tried 20K's and 14K's. I must say I am not that impressed with the 14K's (even though they are Phoenix, so they are more blue). I think I saw about the same growth under both (granted I keep zoas and LPS... no SPS), but my LPS and anemones seemed happier under the 20K's.

[diabeetus]

awesome! great input!! lots to think about. its either 14k or 20k. and i dont think the bulbs that this fixture come with are phoenix so idk if its going to have the same blue look to it, but this fixture DOES have a t5HO actinic supplement on it to help with the color a little bit

[Zarathustra2]

If you have supplemental actinics I would not go with 20K. My tank is almost too blue with just the 20k and no supplements. The 14k or even a 12K should be fine.

Go on down to any of our LFS's and see what they all have.

[diabeetus]

If you have supplemental actinics I would not go with 20K. My tank is almost too blue with just the 20k and no supplements. The 14k or even a 12K should be fine.

Go on down to any of our LFS's and see what they all have.

yeah, i got to thinking and youre right. i dont think i will need the blue tint of the 20k with actinics. but i wonder how a 65k would look with actinics and if the yellow would still be visible? idk, but im probably still going with the 14k. its a good, safe number to be at

[JimD]

6.5k Iwasaki is a fine bulb, yes its very yellow/greenish but with a proper balance of 6.5k and actinics, you can achieve a look thats pleasing to the eye and still get the tremendous growth the Iwasakis are known for. I ran that bulb for many years.

[Starsprinkle Rainbowsmile]

You will also come to find out that the Kelvin "ratings" put on these bulbs can mean very little but marketing.  One 14K will be yellow/white, another very blue, and some right in the middle.  It is better to examine their spectrographs if you can find them, as well as their PAR output.  Also one lamp's "blue" will be a pale blue, another a deep rich blue, and another kind of a greyish blue.

There are differences in T5 lamps as well, and as with anything in this hobby or others, you usually get what you pay for quality wise, although I suppose there are some exceptions.

Hamilton is supposed to make a good lamp; I know their 20K is a very popular bulb as it is supposed to produce the right kind blue to make your corals "pop".