Lighting Questions

[mltnguyen]

Ok all here goes.

 

Sorry if this topic has already been discussed in full detail.

I am looking to setup another tank and had the following questions about MH lighting.

1. What is better DE or Mogul?

2. In a retrofit situation should the reflectors be mounted horizontal or vertical to the tank?

3. What light spectrum is best for growth? (Primarily softies but some stones as well)

4. What types of reflectors would you all suggest as being quality reflectors?

5. Would you suggest buying new or is used worth it? If used is acceptable what things are good questions to ask and what should I be looking for in terms of a quality product. Also what would be a good price range for a duel 400 watt unit (complete)?

6. Do you all find that it is critical to have a chiller with running a duel 400 watt MH? (Just wondering if I can get away with not having one. I have central air and my house stays at a constant 70 degrees year round.)

 

Thanks in advance for your input.

Mike

[andy]

My opinions:

 

1. What is better DE or Mogul?

I prefer SE (mogul). Overall, there is a wider variety of single-ended bulbs available and that selection is more valuable than the additional wattage provided by DE/HQI.

 

2. In a retrofit situation should the reflectors be mounted horizontal or vertical to the tank?

I mount my bulbs parallel to the front/back edge of the tank.

 

3. What light spectrum is best for growth? (Primarily softies but some stones as well)

As a very general rule of thumb, the lower the color temp of a bulb the higher the growth level it drives (10K > 12K > 15K > 20K). Note that there are as many exceptions to this rule as not, so specific research into individual bulb & ballast combinations are a good idea.

 

4. What types of reflectors would you all suggest as being quality reflectors?

Spider/gullwing reflectors are better than flat/no reflector. Luminarc style reflectors are much better than spider/gullwing reflectors. Money spent on quality reflectors is money well spent.

 

5. Would you suggest buying new or is used worth it? If used is acceptable what things are good questions to ask and what should I be looking for in terms of a quality product. Also what would be a good price range for a duel 400 watt unit (complete)?

It depends. An used old magnetic ballast can be a risky purchase since the capacitors age and eventually need replacement (figure $20 per ballast + labor, etc to replace a capacitor). A used, new electronic ballast can be a good buy. Really, it boils down to the specifics of the deal. I don't like buying something used unless I'm saving a substantial percentage over new (like 50% or more). Other people will walk a mile uphill in the rain to save $10. Personal decision.

 

6. Do you all find that it is critical to have a chiller with running a duel 400 watt MH? (Just wondering if I can get away with not having one. I have central air and my house stays at a constant 70 degrees year round.)

I don't think it's an automatic thing. I'm running dual 250W over my 55g and hood & sump fans are able to keep my tank temp down (in an air conditioned room). If my room was warmer, my lights brighter or my tank smaller, the equation would change. Again, it depends.

[chewie]

I'd have to agree with dang near everything Andy said. Especially about people trying to save a buck. LOL Andy

 

The type of tank and lights really makes a difference too.

 

My tank for example, it's a 90g with 1/2" acrylic, with an enclosed canopy with fans and doors. I run a single 400w and 2 55w PC for actinics. The heat buildup is crazy with this type of setup. Even with A/C I need a chiller.

 

On an open top tank with a Pendant style fixture on a glass tank, I think it would be fine w/o a chiller in an air conditioned room.

 

Let us know what you're looking at setting up, and we could probably help alot more, but Andy covered your Q's very well.

[defigart]

When I had my 90G with a canopy the T5's and PC's would heat the water up as much as 3 degrees during the day.

 

Definately the airflow through the area in which the lights are located is very influential in how much heat energy is asborbed by your water. Even with fans the airflow through a canopy is less then it would be through an open topped tank. (Of course unless you use enough fans to create your own mini cyclone.)

[Nyles]

DE bulbs have the advantage of more pendant options for hanging but limited types of bulbs available

As for reflector type a lumenarc will product 20-25% more usable light than a gull wing reflector. As for if you need a chiller, every situation is different, invest in a few fans pointing at sump and put them on a controller or timer.

[mltnguyen]

Ok I have been looking around and it appears that a few manufactures make the Luminarc reflectors. Is one better than others (I understand that this is probable a matter of opinion) but still worth asking. The main reason I ask is I have seen some web sites state “Don’t be fooled by cheap China reflectors” This got me wondering if all Luminarc reflectors are the same or is this a marketing scheme. Anyhow after thinking about this for awhile I thought I would ask some local people.

 

Thanks in advance,

Mike

[andy]

That's an interesting question. I haven't seen any comparisons between original and knock-off reflectors, so can't say with any certainty. I suspect there isn't much performance difference; reflector designs are pretty simple and easy to copy. Smart money says the fit and finish is a lot better on the 'name brand' reflectors though.

 

My preference is to either buy the original (to reward the innovator of the design) or DIY my own knockoff (to save even more money, with the satisfying by-product of depriving those who blatantly profit from the design work of other engineers).

 

In this case, our club sponsor (and local manufacturer) Sunlight Supply makes excellent lighting products

[mltnguyen]

Thanks Andy I will look into Sunlight Supply.

 

Mike

[SamatSLS]

So what did you end up with Mike?

[mltnguyen]

I have not purchased any MH’s as of yet. My tank is a 65G (36Lx24Hx18D) I was originally going to put 1 250MH and run 2x 36” T5s but the more I think about it I think I’m going to run 2x250MH and 2 to 4 T5s.

With that being said I have been eyeing the following.

 

http://www.aquacave.com/galaxy-dual-250w-metal-halide-brretro-kit-with-electronic-ballast-1595.html

http://www.aquacave.com/galaxy-dual-250w-double-endedbrhqi-metal-halide-retro-kit-1962.html

 

Please note I’m still going back and forth as to going HQI or SE and if I should go Pulse or Electronic.

[andy]

Any idea what MH bulbs you want to run?

[mltnguyen]

My first choice is Radium my second choice would be XM.

 

I also think I'm leaning towards the 15k spectrum.

[andy]

I'm running Radiums on a dual Galaxy, 250W. The PAR is good, but the color is rather blue.

[mltnguyen]

Are you running SE or HQI and what spectrum bulb? Do you like your Electronic Ballast or would you stick with a Magnetic?

 

Mike

[andy]

Radiums are 20K SE bulbs. Overall, I like the flexibility that the electronic ballast gives; I can run probe start, pulse start, SE, DE, HQI, whatever. The downside is that the electronic ballast, as a jack-of-all-trades, is a master of none -- it doesn't drive DE or HQI bulbs as well as a magentic ballast would.

 

If I wanted to run only Radium or DE bulbs, I'd probably go with a Blue Wave (SLS magnetic ballast); since that isn't the case (right now) I'm glad I have the Galaxy electronic.

[Brendan275]

One thing also about a retro fit with Hqi is your going to have to put up some uv shield glass since they don't have the glass like SE Bulbs