Yet another lighting question.

[omcnair]

Pardon me but this lighting issue can be pretty hard to figure out.

I have a 72 Gallon tank.

The dimension are 48(L)x18(W)x22(H). I have a 5” DSB and want to keep my options as open as possible. I don’t want to limit my coral choices down the road by making short sighted lighting decisions today. I’ve read a lot of post and done some research.

I’m looking at the following retro kit
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2307278734


It has dual 250w MH ballasts but it looks like it comes with two 175w - 5200k Metal Halide, Clear, by Venture.

Also the kit can drive two 32w 48” Fluorescents. Included are the following bulbs:

Coral Sun Actinic by ZooMed (Quantity: 2)
Ocean Sun 10,000k by ZooMed (Quantity: 2)

So Questions:
Is this enough and the right kind of light for what I’m looking to do?
Should I upgrade the 175w bulbs to 250w bulbs?
What about the choice of fluorescents tubes (Coral Sun and Ocean Sun)? Should I look at alternatives to what’s included with the kit?


Thanks in advance.

Oliver

 

[reefrunner69]

[center:67a3dfec2e]Metal Halide
Reef Aquarium Light
Retrofit Kit

Nominal 48 inch Version

DUAL
250watt Metal Halide
Retro Reef Kit

Includes
2x250w-5200k Metal Halide Bulbs
plus
4xZooMed fluorescent bulbs!

(supporting a variety of bulbs ~ 5200k-10,000k+)

Professional Grade Equipment

All items are "Mint-New" from Factory Fresh Inventory

Never used-never installed. [/center:67a3dfec2e]

Depending on the selling price, it looks like a good deal. I didn't really look it over too much, though. It requires 250W bulbs and comes with them, although I would highly recommend you upgrade the bulbs to 6500K-20K depending on what look you want for your tank. You may also need to upgrade the flouresceant bulbs as well. With the proper spectrum...that kit will meet your needs and allow you to grow anything you want.

 

[Anemoneman]

175W is fine for a 72 gal. 250W is better and gives you the option of using Ushio 250W 10000K bulbs. With the 5200K MH blbs supplied you will want to use the pure actinic NO flourescent tubes, not the 10000K tubes.
It either comes with 175W ballasts or 250W ballasts. You can't run 175W bulbs off a 250W ballast and vice versa. Not sure why their listing a 175W bulb with a 250W ballast. Their ballast is electromagnetic which, if I'm not mistaken, is a basic core and coil ballast. Not the best but it will work. The nonsense about 3rd world an US ballasts oly lasting 6 months is baloney. I have used 2 175W Sola ballasts form Mexico (an ISO-9000 rated company) for a few years now. There is no difference. Transformers don't vary much in quality IME. You can put together a DIY for less money but this is a nice kit. If you want to go top quality, get electronic ballasts for the MH and the NO flourescent. I would still shop around. Ebay doesn't always have the best deals IMO. You may get a good price at the expense of quality or desired features. Don't believe all the BS these guys put in their auctions (this guys's got quite a load!). Do your own research, sounds like you have, so you know what you get.

Mark

Here is a good retrofit 250W magnetic ballast w/reflector for $85. http://www.hellolights.com/25methalretk.html
All you need is 2 of these and 2 10000K bulbs - no flourescents needed.
Total cost would be around $370 for comparison.

 

[reefrunner69]

I sent the guy an email letting him know he has it listed two different ways in the auction. We'll see if he fixes it.

 

[omcnair]

Thanks for all the good advice so far but what is a proper mix for the bulbs/tubes?
I hear that I need bulbs in the 6500k to 20,000k range all the time but what does that really mean?

I know that k refers to the color temp of the light and that 5000k bulbs have illumination properties that mimic sun light at noon and that the higher you go up in kelvins the more that the presence of blue light exists - but what does it all mean in nature’s terms?

Blues (20,000k) in the morning and evening and 6500’s all the rest of the day?

 

[Anemoneman]

No. High Kelvin temp bulbs (10000K) mimic the light that reaches 5-10 meters deep in the ocean. It isn't mimicing morning and afternoon light. 5000K is the sun. 10000K is what the sun looks like 10 meters deep where our corals live. Since our tanks are much shallower (measured in inches not feet) we can simulate that by using higher Kelvin bulbs.
You can do it by using 10000K - 20000K MH or adding actinic which supplements the blue spectrum.

Mark

 

[omcnair]

Wonderful, this is beginning to finally make some sense.

May I pick your brain one last time on this subject at least. So the Actinic provides blue light to off set the yellow (or washing out) from other bulbs like 6500k and 10,000k? Are actinics used mainly for their visual effect?

Also, I've heard 6500k bulbs referred as growth bulbs. Is that correct? If so, why? Why would a 6500k bulb be better for growth then say a 10,000k or 20,000k bulb?

 

[Anemoneman]

Some people report greater growth rates of SPS coral under 6500K than under 10000K. Actinic supplements are for visual appeal but also add to the amount of light in the blue end of the spectrum reaching your corals. The aesthetic effect is to offset the sightly yellow/green tint of lower Kelvin bulbs. Use them with bulbs 6500K and lower (no lower than 5500K for a reef tank).
Another point, many bulbs are advertised as 10000k or 20000k but really aren't. A case in point were two members who bought a new bulb advertised as 10000k but was visually more like 4000K. Both returned them for Ushio 10000k. German bulbs are generally as advertised as are Ushio. I believe Hamilton are reputable also. Personally I would not go higher than 10000k. Too much blue can wash out some of the vibrant colors.

Mark