Sanjay or anyone please help me light my 47 gall extra tall

[pjf]

Another Thread

Another Thread

There is some additional information about 150-watt versus 250-watt HQI lighting in the Advanced Topics forum. The thread is “Light Intensity & Effectiveness. Experts please” and is located at the following link:

http://www.reefcentral.com/forums/showthread.php?s=&threadid=975037

One contributor to that thread states that SPS corals near the surface will be photo-inhibited by the 250-watt HQI over a long photoperiod and suggests dimmer lighting.

The problem with deep tanks is that a single overhead MH light may photo inhibit the corals near the top while starving corals near the bottom. There are different ways to solve this problem. My “two-cents” for tall narrow tanks is to:

(1) Aim for a long viewing photoperiod if there is no room for supplemental lighting
(2) Obtain the strongest light that will avoid photo-inhibiting the corals at the top
(3) Depend on reflection to get light to the bottom
(4) Ensure adequate water flow, water quality and water temperature.

 

[The Grim Reefer]

Noon time sun exceeds 2000 UMOL's at the water surface on a clear summer day at a reef. You would have to mount even the best 250 watt HQI right at the water surface to match that intensity. Assuming you did that would the corals just under the surface of the water receive more light than they need? Yes, JUST LIKE THEY DO IN NATURE. The corals will also be subjectd to that light better than 12 hours a day.

The question to ask is will a 150 watt halide provide enough light for a brain coral on the sand of a 30" tall tank. Answer, no way in hell. I measured the PAR of 10K 150 watt halides running with PC actinics over my 125. The PAR sensor was 18.5" under the water surface directly below a lamp. Even with the fixture mounted 1" above the rim of the tank I only got PAR of 95 at the sandbed. That wasn't enough to keep a moderate light montipora digitala happy when it was sitting on a rock a few inches above the sand. Aint no way a brain coral on the sandbed of a 30" tall tank is going to have enough light to survive.

 

[pjf]

<a href=showthread.php?s=&postid=8630149#post8630149 target=_blank>Originally posted</a> by The Grim Reefer
Noon time sun exceeds 2000 UMOL's at the water surface on a clear summer day at a reef. You would have to mount even the best 250 watt HQI right at the water surface to match that intensity. Assuming you did that would the corals just under the surface of the water receive more light than they need? Yes, JUST LIKE THEY DO IN NATURE. The corals will also be subjectd to that light better than 12 hours a day.

The question to ask is will a 150 watt halide provide enough light for a brain coral on the sand of a 30" tall tank. Answer, no way in hell. I measured the PAR of 10K 150 watt halides running with PC actinics over my 125. The PAR sensor was 18.5" under the water surface directly below a lamp. Even with the fixture mounted 1" above the rim of the tank I only got PAR of 95 at the sandbed. That wasn't enough to keep a moderate light montipora digitala happy when it was sitting on a rock a few inches above the sand. Aint no way a brain coral on the sandbed of a 30" tall tank is going to have enough light to survive.

Grim Reefer,

Good points. What photoperiod is recommended for 250 HQI lighting? Under what circumstances can you photo-inhibit SPS corals near the surface with hood-mounted 250 HQI lighting?

Thanks!

 

[The Grim Reefer]

The trick is going to be placing the corals. Right now I am running T6 VHO flurescents and after about 6 hours my Frogspawn is hating life. I mounted it about halfway up the rocks, big screwup. The Acros and Montis up on top of the rocks are loving it.

Point is think about where you place the corals and watch what they are doing. In an nice halide/actinic system you can probably get away with 4 or 5 hours of halides a day. If corals are placed right 8 to 10 hours a day are not going to hurt them. Hard corals can exposed to the air at low tide many times, they are pretty adaptable to a lot of conditions. The ones they can least adapt to is poor water quality and lack of light.

 

[Chihuahua6]

Here's what I came up with. As per the recommendation of Sanjay and Eric Borneman I am going with the 250 watt HQI. Eric said 175 or 250 watt and Sanjay recommended 250. Without going into the why, what, photoperiod etc. the solution I have come up with I think will address both points mentioned by The Grim Reefer and pjf. (BTW do you guys have names?) ; )
I decided on the Icecap pendant and Icecap ballast for quality, long term reliability, future use (it can take a 250 or 400 watt bulb) and the fact that it's an electronic ballast which can take any bulb. In addition to the pendant I am going to try and install a PC strip with actinic bulbs and moonlights. Since I have 6" of room if I place the pendant slightly toward the front of the hood I think I may be able to build the PCs into the hood especially since the hood will be custom made by my husband. I will probably leave the top of the hood and/or the back open for ventilation and add fans on the sides. The top won't be seen anyway since the tank is so tall. I will just add a brace to hold the pendant and another to attach the PCs.
Now I can put the actinics on for a few hours. Then turn on the halides for up to six or seven hours a day (just guessing here). Then have just the actinics on for a few hours and have the moonlights come on for a few hours into the night for night viewing since I go to sleep around midnight. What do you think? Not bad for a chick huh?

 

[The Grim Reefer]

Normally it is better if you can have an actinic at the front but that might not work in your case. I'd stick with a DE halide lamp because of the tighter focus.

If you use a 14K lamp you will only really need the actinic for dusk/dawn so the PC placement wont be as important. You might actually be better off not using actinics and using high powered LED moon lights for dusk/dawn instead.

 

[Chihuahua6]

Yes a DE halide is what the pendant takes. I don't know if I would get enough flourescence with just a 14000k bulb which is why I thought the actinics would be nice. I have only used 10000k bulbs with actinics in the past and I liked the color. I have never seen moonlights in person either so I hadn't considered whether or not they would give off enough light to view the tank in the morning and early evening when the halides go off. Do you have any pics or a link of a tank lit with only LED moonlights?

 

[The Grim Reefer]

Don't have a pic but check out some of the online retailers. They will have pics. They will have enough for viewing but it isn't as nice as actinics. You could probably cram at least one PC in there.

 

[pjf]

Lighting Trends

Lighting Trends

Grim,

Is there any consensus on the optimal PAR range for SPS? My understanding is that SPS corals are photoinhibited during mid-day and are photosynthetically most active during morning and afternoon periods when the light is less intense. Dana Riddle found dynamic photoinhibition in Montipora at 260 µmol•m2•sec with photoprotection beginning at ~100 µmol•m2•sec. In fact, he found greater photosynthetic activity with ambient room lighting than with MH lighting at 800 µmol•m2•sec (http://www.advancedaquarist.com/issues/july2004/feature.htm). If this is verified in practice, the PAR you measured at your sand bed does not seem unreasonable.

As the industry moves towards less intense LED lighting, I am sure that this issue will be discussed more and more. In the latest volume 3 of Delbeek & Sprung’s The Reef Aquarium, there is a reference to Riddle’s article but missing is recommended lighting levels.

Chihauhau6,

Thanks for the feedback regarding your plans. I notice that Borneman may have hedged when he mentioned 175w lighting. He must have known that 150wHQI lights are just as bright. Did Dr. Joshi explain why he thought 250wHQI was more appropriate for your system?

Thanks!

 

[The Grim Reefer]

Sanjay recoed 150 at the sandbed for an SPS tank but said 100 if you are carefulabout coral placement.

 

[pjf]

Thanks, Grim, for your great information.

I've read your posts intently and you are definitely one of the reasons why I am a fan of Reef Central. In fact, based on your T5 postings, I am trying to retrofit an old MH+NO fixture with T6 tubes and new ballasts.

I think your posts are also reassuring the early adopters of LED lighting. I may take the LED plunge next year if I can't get my ancient MH+NO fixture working properly.

Have a Happy Holiday Season!

 

[The Grim Reefer]

I am not sold on LED's yet. It is pretty easy to get a lamp or ballast when something goes wrong. With LED's so far you have to ship the whole thing back to the factory. I would wait until they come out with a modular unit.

 

[The Grim Reefer]

<a href=showthread.php?s=&postid=8670950#post8670950 target=_blank>Originally posted</a> by pjf
Thanks, Grim, for your great information.

I've read your posts intently and you are definitely one of the reasons why I am a fan of Reef Central. In fact, based on your T5 postings, I am trying to retrofit an old MH+NO fixture with T6 tubes and new ballasts.

If you are going straight fluorescents I would probably stick with T5's because of space, the T6 reflectors are wider.

What part of CO you in?

 

[pjf]

I agree that T5 is better than T6 if one is looking for a new fixture.

I have an ARAD HLD-1250B (www.arad.us) MH+NO fixture:

Since T6 & T6HO bulbs fit into NO sockets, that seems to be the way to go in order to get a bit more output (~10%). I would replace the NO ballast with a T5 ballast if I can find one short enough to fit within the confines of the fixture (~5"x5").

I see that you are in Aurora, Colorado. I am in Monument and although I rarely head north, I would appreciate it if you can recommend a good LFS, frag shop or reef club in the Denver metropolitan area. Thanks!

 

[The Grim Reefer]

For a Club there is one based around the springs, hit the club forums, it the Southern Coloradomething or other. There is also Rocky mtn reef club and DARC around Denver. Keys Island is a great LFS and Snow Cap in the Springs is a good place.

I am running T6 VHO's on the new tank, so far so good. If you are just changing out for suppliments the T6 will be good. They hold up to heat a lot better than T5's.

 

[pjf]

<a href=showthread.php?s=&postid=8670682#post8670682 target=_blank>Originally posted</a> by The Grim Reefer
Sanjay recoed 150 at the sandbed for an SPS tank but said 100 if you are carefulabout coral placement.

Grim,

In what article did Dr. Joshi say this? He's written quite a lot and I must admit that I haven't read all of his publications.

Thanks!

 

[The Grim Reefer]

This was on his lighting thread.