Lighting Questions

[jlearned]

OK so I have some questions regarding MH lighting. I have built a DIY hood that is 62x19x14. My tank is 26" deep. I plan on having a 2 to 2-1/2" sand bed. The hood itself overlaps the top of the tank by 2 inches which will be just below the water level. So I figure that I will have a 22 inche column of water to light.

Will 175W MH be enough? I want to have a combination tank of softies, LPS, and SPS. I will be supplementing the MH with T-5's, Pure Actinic bulbs.

If 175W is not enough will I have a major issue with heat build up with the 250's in an enclosed hood?

I built the hood with 1" slits running across the back to vent heat and I plan on installing 2 fans at the ends to bring in fresh air.

-Jason

 

[fishoutofwater]

my new tank is 60x25x18 and i am going with the dual 250's with 4- t-5's due to its depth. i would add a fan to the hood to exhaust the heat. this should be done with 175 /250/400 in my opinion too. but def go with 250's u will be happy u did.

 

[Myteemouse]

have one fan sucking in and one blowing out. Yoiu'll keep the air fresher in the hood and the lamps and water cooler!!
The vents are good but you might want to have the fans working in tandem..

 

[JasonD]

What bulbs and ballast are you going to run? It makes a huge different.

The 15,000K Iwasaki - 175W, will outperform some 250W bulbs.

What is your color preference?

Some of the higher k 175W bulbs are very poor performers.

Your can compare bulbs and ballasts here (Sanjay Joshi - spectral plots)
http://www.manhattanreefs.com/lighting

I like the higher K, "blue look". I have a 2 250W 20 XM bulbs on coralvue electric ballasts. The tank is 60l x 24w x 20d. I keep SPS at the top and middle of the tank and softies/LPS at the sides/middle and on the sand bed. The lighting is a little week in spots. I do not have any supplemental lighting, but I was planning on adding some actinics.

 

[jlearned]

have one fan sucking in and one blowing out. Yoiu'll keep the air fresher in the hood and the lamps and water cooler!!
The vents are good but you might want to have the fans working in tandem..

Good idea Ill give it a try.

What bulbs and ballast are you going to run? It makes a huge different.

The 15,000K Iwasaki - 175W, will outperform some 250W bulbs.

What is your color preference?

Some of the higher k 175W bulbs are very poor performers.

Your can compare bulbs and ballasts here (Sanjay Joshi - spectral plots)
http://www.manhattanreefs.com/lighting

I like the higher K, "blue look". I have a 2 250W 20 XM bulbs on coralvue electric ballasts. The tank is 60l x 24w x 20d. I keep SPS at the top and middle of the tank and softies/LPS at the sides/middle and on the sand bed. The lighting is a little week in spots. I do not have any supplemental lighting, but I was planning on adding some actinics.

I have spent the most of the last 2 days at manhattansreefs.com and thought if I went with the 175W lights I would use the Iwasaki 15000K as they have one of the highest PPFD values ran on IceCap Ballast. I like the colors I have seen in the 15000K area. But I have not seen a 20000K lighting in person and I am afraid it might be too blue for my taste but I do agree in the photos it makes the colors pop. If I went with 250W setup I was looking at XM 10000K with the IceCap ballasts. Both setups seem to be great performers.

 

[saltybell]

I would do the 250's personally. I ran dual 250's on my 90 gallon and thought I would switch to dual 175's for power and heat savings (neither was enough to notice) . I was not happy with the performance of the 175's so I am back to the 250's.

 

[jlearned]

I would do the 250's personally. I ran dual 250's on my 90 gallon and thought I would switch to dual 175's for power and heat savings (neither was enough to notice) . I was not happy with the performance of the 175's so I am back to the 250's.

What bulbs were you using with the 175's and how deep was the tank? I too am interested in saving in power and heat but I dont want to be disappointed with the performance of the 175's.

 

[saltybell]

I was using reeflux 12k's SE with lumen bright reflectors and the tank is 24" deep.

 

[AZDesertRat]

One fan blowing in and one out is a waste of a fan. You only get the CFM of a single fan. The second fan only moves the same air the first fan sends it and no more. This is true if the canopy is enclosed as mine is.

Two fans, one in each end both blowing in and equal sized or larger exit holes either in the top or high up on the back close to the center is a much more efficient way to move air. You get the CFM volume of both fans plus you take advantage of natural convection since heat rises.
By using this method my chiller never runs any more and thats in Phoenix in the dead of summer. The fans are vantec Stealth 120mm DC computer fans found at newegg.com for like $11 each and are powered by small "wall wart" type DC variable voltage power supplies that can be found anywhere for less than $10 each. One power supply will easily power up to 3 fans and with the variable voltage you can dial in the fan speed for your needs.

As for the 175w MH, you should be fine. I had 2x175w (first Ushio 10k and later XM 10k) on my 100G 60"x18"x23" high tank for the first year or two and SPS and LPS grew like weeds. I now have 2x250w and there is not a huge difference in noticable light output. I supplemented with 2x140w VHO Super Actinics but now use Reeflux 12k bulbs and rarely turn the actinics on today since the color is great even without them.

I was using reeflux 12k's SE with lumen bright reflectors and the tank is 24" deep.