175W 20K BUlb Options

[nine9d]

Hey all,
I am looking for a good 175W 20K bulb to get more pop out of my corals. I love the blue hue's. Does anybody have any preference of one over the other? I have a Hamilton Fixture with a probe start m57 ballast if that matters to you. I have seen some data on bulbs, but would much rather if someone has first hand experience with the way it looks. I have a bunch of different types of bulbs now like the Iwasaki 15k, some Hamiltons and others, but nothing that I am thrilled with as far as making my corals have a nice blueish pop to them. Thanks for your help.

 

[Toddrtrex]

What size tank?

I tried a 2 175 20K (( XM )) over my 58, and while I liked the blue look, they were just too dim overall for my tastes. I ended up getting a new 2*250 ballast (( Using a full Hamilton fixture )), and using the 250 watt XM 20Ks, and love it.

 

[nine9d]

It's 18" deep, thanks for the response. Anyone else? I am open to any bulb out there.

 

[grigsy]

The two 175 watt 20K bulbs I like are the XM 20K and Hamilton 20K. Both good bulbs IMO.

 

[reef.fishman]

as a rule of thumb, if you have something like a 10k bulb and you want to change to a 20k bulb, you're going to have to increase the wattage to keep the overall light levels the same. essentially, then, to go from 10k to 20k you're going to have to go from 175w to 250w.

 

[nine9d]

Thanks for all the input thus far. Anyone else have any experience with some 20k bulbs as far as looks go?

 

[reefscape15]

I just added a 20k 250 XM single ended and it looks awesome~! I do wish it was a tiny bit bluer, but i'm taking the 12k t-5 out and adding another actinic. Hopefully this will help me

 

[reef.fishman]

you haven't mentioned how deep your tanks are, or how many 175W bulbs you're using. those are key pieces of information.

for your probe start M57 ballast, the XM 15,000k and 20,000k bulbs have nice color at a fairly cheap price. the problem is that the PAR values for the 175W version of these bulbs are horrible. the color will be nice, but your tank will look dark. i would predict that you will be disappointed with the total light output unless you bump up to 250W.

just for reference, i tried a 175W, XM 15,000k bulb on an IceCap ballast. the color was nice -- bluer than i had expected -- but the level of illumination was horribly dark. 175W just wouldn't cut it at the higher color temps. so i went back to 10k @ 175W or 20k @ 250W for my shallow tanks. for my deeper tanks its 10k @ 250W or 20k @ 400W. the two bubls within each of those combinations puts out comparable PAR values.

hth.

 

[nine9d]

Thanks for all that great info. I hear what you are saying about the PAR and all that jazz. Someone told me today that the ICECAP bulbs were nice, anybody know? I was trying to get the best color as it is just a frag tank. Thanks.

 

[reef.fishman]

i don't know about icecaps. being a contract manufactured / rebranded item, they can't be anything unique.

FYI the par numbers are better on the XM 20,000k than the 15,000k. the 15,000k is just a dim bulb. they should either change the fill formula or discontinue the bulb. what's the point of a 15,000k bulb that has lower par than its 20,000k counterpart?

your use of the term "frag tank" is still somewhat nebulous. depth is what's important. i wouldn't hesitate to use the XM175 20,000k bulb over a shallow frag tank -- something 12 inches or less, but i would be reluctant to use it above 18 inches of depth. IME its just not bright enough.

 

[nine9d]

Thanks bud for all of your help, it is greatly appreciated. If anyone else has info. thanks in advance.

 

[RoscoPColtrane]

I like the look of the Hamilton 14Ks on the M57 ballast. My corals look great under these bulbs. I wouldn't want to go any bluer in a 175W bulb. It's really a matter of personal preference, you will get many opinions.