ATI 6x39 or 6x24 over 36"x24"x20"

[Patrick Cox]

Currently I am running an Aquatic Life 4x39 watt 36" fixture over my 36x18x21 aquarium. I have several LPS corals that have done very well under this light. My SPS are really just sustaining but they are not really growing.

I am currently building a 36x24x20 inch aquarium and I plan to use an ATI Dimmable Sunpower over this tank. I have had in mind that I would go with the ATI 6x39watt 36" fixture but I have been reading some posts about this fixture being too much light for LPS and also about problems with light spillage. I don't think light spillage will be a problem for me on the front or back because my aquarium will be 24" front to back. However I am not sure about the ends. Although my current 36" light fixture does not spill much light on the ends of my current 36" tank. Also, the new fixture will only be adding two new bulbs but I have read that the ATI fixture will reflect a lot more light than other fixtures. I have two very nice LPS corals that I don't want to bleach/lose (Elegance and Frogspawn) so I want to make sure I don't over do it on the light. However I also want to add some SPS to the new tank so that is another concern.

So bottom line, should I have any concern about the 6x39 fixture burning my LPS corals or about added light spillage on the ends? If not, I think that is the more flexible solution.

Thanks!

[daveonbass]

like I said before...it's totally possible...but you will be best running it higher off the water at first. Also...how High is your current fixture of the surface?

I would say to either get the 8x24, or the 6x24. If you think you'll ever want to upgrade to a bigger tank (48") then I'd say do like me and get the 6x36. I DO think that the 8x36 will be WAY over kill for that size tank.

Case in point is the current TOTM on the home page. The light is smaller than the tank foot print on all sides...and it's still raised up a good 6" or more off the surface of the water. And that's a beautiful SPS and mixed tank.

[daveonbass]

double post

[Patrick Cox]

Originally Posted by daveonbass

like I said before...it's totally possible...but you will be best running it higher off the water at first. Also...how High is your current fixture of the surface?

I would say to either get the 8x24, or the 6x24. If you think you'll ever want to upgrade to a bigger tank (48") then I'd say do like me and get the 6x36. I DO think that the 8x36 will be WAY over kill for that size tank.

Case in point is the current TOTM on the home page. The light is smaller than the tank foot print on all sides...and it's still raised up a good 6" or more off the surface of the water. And that's a beautiful SPS and mixed tank.

Thanks. My current fixture is on legs so I would say it is about 3 1/2" off of the rim and about 5" or so above the water line. I think the difference on the new fixture (ATI) is that it is supposed to project a lot more light into the tank. But again, corals are fine with this light and I have little spillage.

What is also confusing to me about this discussion is that when I was considering MH, everyone was saying I needed at least 2x175 MH bulbs plus a couple of actinics and the 2x175 MH bulbs alone draw almost 50% more watts than the 6x39 fixture so I don't see how the 6 39 watt T5 bulbs will produce too much or even borderline too much light? I think I am reading too many posts on these forums!!!

[maysorum]

These lights are very powerful and have impressive individual reflectors! I have a 8x54 PowerModule on a 47.25 x 22.5 x 20 tank and have to keep the light at least 11" above the surface. My coral are all located at least 10" below the surface, so the light is 20" above the tallest coral. I have bleached SPS mini colonies that I have sitting on the very bottom when the light has been lower than 10".

[daveonbass]

I agree with MAY. I've bleached many high light corals by having stuff just IN the tank even as low as the sand...in the shade.

Patrick: throw out the watts per gallon rule. The only time it applies is when you compare MH to MH. Other light forms are far more efficient and therefore use less energy/heat. T5s are one...and so are LEDs. If we used 150w worth of LEDs to replace one 150w MH bulb...roughly 50 LEDs...put proper optics on...and ran them at full power...you'd have a beautifully bleached tank.

[Patrick Cox]

Ok, let me try it this way. How would you compare the light output of the two fixtures below? Is there anything in the spec sheet that will give an indication of the light output?

My current fixture: (Aquatic Life)
http://premiumaquatics.com/aquatic-s...AL-420036.html

ATI 4-bulb fixture: (This is not my fixture but my current tank is only 18" deep and my new tank is 24" deep with an external overflow box. Thus the addition of 2 lamps. Question is, how much more powerful is the 4 lamp ATI to my current?)

http://premiumaquatics.com/aquatic-s.../ATI-3307.html

Thanks.

[Saltwatercoral2]

I have the 36" ATi 6 bulb fixture over the same exact tank, and Its just mainly a zoa tank. i have a hammer, torch, frogspawn and an anenome in there. Everything seems happy.

If you go with the 24 inch fixture, I would get an 8 bulb fixture, but if you go 36" inch just get the 6 bulb.

[Patrick Cox]

Originally Posted by Saltwatercoral2

I have the 36" ATi 6 bulb fixture over the same exact tank, and Its just mainly a zoa tank. i have a hammer, torch, frogspawn and an anenome in there. Everything seems happy.

If you go with the 24 inch fixture, I would get an 8 bulb fixture, but if you go 36" inch just get the 6 bulb.

This is what I was thinking. Thanks. I will report back.

[daveonbass]

that's what I think too...24x8, or 36x6. the 8 bulb would actually be better over all becasue you could really refine the color and look in the tank. I'm still surprised at how limited I am with only 6 bulbs...and I don't know what I'd do with only 4.

to answer your question on the comparison...

I don't have solid numbers on any PAR measurements...but I would guess that the ATI puts out at least half as much MORE light than the AL. So if the AL fixture has a brightness of 20, then the ATI would have a brightness of 30-40. btw, these are completely made up numbers...I am only using them to illustrate that the ratio of light between the ATI and the AL fixture is 3:2 (less than double)if not 4:2 (which would be double).

[rtparty]

8x24 is my vote. 36'' t5s actually have the worst PAR per watt for some reason.

Sent from my SCH-I535 using Tapatalk 2

[maysorum]

Originally Posted by Patrick Cox

Ok, let me try it this way. How would you compare the light output of the two fixtures below? Is there anything in the spec sheet that will give an indication of the light output?

My current fixture: (Aquatic Life)
http://premiumaquatics.com/aquatic-s...AL-420036.html

ATI 4-bulb fixture: (This is not my fixture but my current tank is only 18" deep and my new tank is 24" deep with an external overflow box. Thus the addition of 2 lamps. Question is, how much more powerful is the 4 lamp ATI to my current?)

http://premiumaquatics.com/aquatic-s.../ATI-3307.html

Thanks.

You can't compare apples to oranges. This light is powerful, I have had a hard time with my torch, hammer, and acans. They are extremely low in the water column and have to be kept on the outside edges of the tank. There is NO way you can keep this fixture 3.5-5" above the surface. Also, light spillage is a non-issue (unless you don't like the look) since there is SOOOO much light.

Maybe this will help:

24" 6x24W
Common Sizing Guideline: soft coral tanks up to 70 gallons, mixed reef tanks up to 60 gallons and SPS dominated tanks up to 50 gallons.
- Recommended Tank Depth: up to 30" with carefully planned placement of corals.

24" 8x24W
- Common Sizing Guideline: soft coral tanks up to 95 gallons, mixed reef tanks up to 75 gallons and SPS dominated tanks up to 60 gallons.
- Recommended Tank Depth: up to 30" with carefully planned placement of corals.

36" 4x39W
- Common Sizing Guideline: soft coral tanks up to 80 gallons, mixed reef tanks up to 60 gallons and SPS dominated tanks up to 50 gallons.
- Recommended Tank Depth: up to 30" with carefully planned placement of corals.

36" 6x39W
Common Sizing Guideline: soft coral tanks up to 115 gallons, mixed reef tanks up to 95 gallons and SPS dominated tanks up to 80 gallons.
- Recommended Tank Depth: up to 30" with carefully planned placement of corals.

36" 8x39W
- Common Sizing Guideline: soft coral tanks up to 160 gallons, mixed reef tanks up to 125 gallons and SPS dominated tanks up to 105 gallons.
- Recommended Tank Depth: up to 30" with carefully planned placement of corals.

[Patrick Cox]

On the 6x39 fixture, what if I use one or two actinic bulbs instead of Blue +. I was thinking since they have less par that would help reduce the possibility of too much light. I already have this ATI fixture but it is still in the box as my tank is not built yet so if it really is too much light, I can exchange. Also I is a dimmable fixture.

[daveonbass]

Two actinics is a good idea, its what I ended up doing with mine at first when all my corals would bleach and die. After 6 months though i wanted better color in the tank and got bulbs with more par, and then chose to raise the light to 14 inches as a trade off.

[kc350twin]

I agree with the current opinions so far. I would use caution with the LPS. I have to keep my favias and plates damn near in complete shade with the SP's 10" off the water. I also only run my main lights only 4hrs a day with the actinics and led's on for the majority.




Kc3

[kc350twin]

I agree with the current opinions so far. I would use caution with the LPS. I have to keep my favias and plates damn near in complete shade with the SP's 10" off the water. I also only run my main lights only 4hrs a day with the actinics and led's on for the majority.
Start high and work your way down. I think light spill is inevitable when running these and no canopy.




Kc3