Going VHO vs MH

[Bearfan]

I'm researching new lighting for my 75gal and was wondering the advantages between VHO and MH. From what I read, VHO runs cooler.

I debating between 7x110 VHO (5 daylight, 2 actinic) or 2x250 MH + 2x110 VHO actinic.

Anyone want to suggest?

 

[MarineFlake]

I run 4 VHO's (2 actinic blues, 2 actinic whites) over my 75G and everything is good..MH would roast my tank in the summer considering I would need at least a pair of 250w 12k or 14k mh to do the same work. Heat will most definitely be your enemy with MH.

 

[Salttanker]

Heat is definitely an issue with MH, but if you build the canopy high enough and add a couple of fans it will only change within a degree or two. I love mine. The shimmering effect is pretty awesome too. I have the 14K Coralvue's and can run them without supplemental lighting. It offers a nice white, and blue balance. In fact, I just use my actinics without the whites on my pc for the dusk to dawn effect.

Mike

 

[msuburg]

I'm currenly setting up my 75g, and I think I'm going to go with the VHOs myself. The MH scares me a bit with the heat. And I don't think my canopy is going to end up being that high off the water for the MH.
With the VHOs, should I just go with 4 of them, 2 actinic white and 2 blue? What differences would it make to do different numbers of these - say 3 white and 1 blue? Is it just shifted towards one end of the spectrum? Or should they always be equal, such as 2 x 2?

TIA

 

[Phyl]

Will you get the same light penetration with VHOs that you would get with MH? This whole lighting calculation has be a bit confused. It seems like light penetration would be more important than WPG. Sure I could put a second light just like my first over my tank but the bottom would still be getting the same intensity of light (just more of it)... What is the penetration difference between VHO & MH? Is it comperable? Could I double my PC and get to the same place?

 

[bound_for_obx]

Couldn't you get by with 2x175 MH and 2x110 VHO actinic? You are only talking about penetrating about 16 inches of water with a 4" DSB in a 75 gal tank. You would have less heat to worry about and I would think that that would be plenty of light. It would cost a little less to set-up, operate, and replace bulbs as well.

 

[MarineFlake]

I have a 150w MH w/2 65w blues over a 29G and it can take the temp 2 degrees up over 5 hours. It very much depends on what the temp is in the room. This tank is upstairs and the temp (room t emp) can be controlled much better up there than in my downstairs. I imagine during the summer its going to be very hard to keep the temp in the mh tank stable as it will get very hot where I live in the summer (Can get into the 100's easy). My point being, that if you live in an area where you can expect very hot temps outside, you can expect its going to get pretty warm inside. If the temp in your house is 78, the tanks going to be *at least* that much which means another 5 - 8 hours of mh lights (even dual 175's) are going to cost you another couple degrees (Min). So at the end of a 5 hour cycle your tank temp would be about 80.? degrees. Now, barring the fact you may have a pile of money or an industrial AC unit on your house, you'll probably end up with a chiller, running your AC all the time every day through out summer or dealing with high tank temps (usually treated by moving the cycle to cooler evening hours and using a fan (like a room fan) to blow across the lights to try and exhaust some of the excess heat..Great for the fish, not so much fun for the rest of the family..). All that said, even using 4 VHO's I get a degree or two of flux and during the summer my tank can easily start to reach 82.? degrees. Its a given that mh produces more heat and that can only mean higher temps. You can put what ever wattage bulb you want over the tank, the fact is mh *is* hotter and will cause substantially more temp issues during warmer weather. Again, I have seen chillers used, I have seen folks run their thermostat (in the house) around 74 - 72, but imo, thats not practical. I can't afford a $250/month cooling bill ; ) So in the end, you either realize mh may cost you a $400 - $800 chiller (plus the cost of running that each month) or run cooler lighting/change the light cycle to cooler hours..Not much fun to look at the fishies in the dark when you get home from work..
Just punchin' in with my experience, some of you surely live in cooler climates and may not have this issue.

GL!

 

[MarineFlake]

Sorry was goign to post this too, hit submit instead..
Taken from http://www.marinebiology.org/coralbleaching.htm ...
"
Temperature

Coral species live within a relatively narrow temperature margin, and anomalously low and high sea temperatures can induce coral bleaching. Bleaching events occur during sudden temperature drops accompanying intense upwelling episodes, (-3 degrees C to –5 degrees C for 5-10 days), seasonal cold-air outbreaks. Bleaching is much more frequently reported from elevated se water temperature. A small positive anomaly of 1-2 degrees C for 5-10 weeks during the summer season will usually induce bleaching. "

Alot of issues are temp related most folks don'realize it. Not trying to say mh is evil (I have mh!) but be prepared to deal with the heat issue. Know your coral, in some instances it only takes a degree or so to cause the symbiotic zooxantheallae to start to die off..

GL!

 

[scuba_steve]

bearfan with your huge sump in the basement you wont have an issue with heat ! id go with 250watt hqi 20000k and no need for o3 supplement

 

[Salttanker]

One thing to keep in mind is replacing bulbs every 6 months or so with VHO. If you have 7, that will get pretty expensive. MH bulbs are more expensive (mine are $56.00 each), but replacement is within a year, and that would only be 2 of them versus 7 every 6 months. I like Keith's idea with going for the MH with the 20K. 2 of those, and no additional supplementation would be ideal for a 75. Food for thought..

Mike

 

[ellisz]

I have a 2x250 MH setup on my 75 gal. I will agree on the heat issue but I also have a closed canopy. I seem to have more issues in the winter though.

Room temperature will be the key. My wife likes a cool house so summer is not a problem. My lights do heat the water about 2 degrees. I have 2 80mm fans blowing out and 1 120mm fan blowing in.

I know a guy with a 125 gal and a 3x250 set up and he does not have heat issues but his canopy is suspended and open to the air. He does have a small fan that blows across the surface of the water.

I went from PC lights to MH and the look of the MH's is worth it IMO.

HTH

 

[Bearfan]

So I don't need Actinic, but what if I like the cool effect it has on a bunch of my coral? I would miss seeing the zoos and star polyps glow. I've seen some fixtures that have both, so maybe that's my solution 2x250w 20k hqi and 2x32w pc actinic.

 

[Salttanker]

That sounds good Bearfan. I use 2 250W 14K MH, and the Corallife 4x65w pc. The only part of the Coralife retro I use is the actinics. I don't care for the white so much, but with the 14K bulbs, and the Coralife actinics (dusk to dawn effect) I get the color hue I have been looking for. Not only that, but you will love the shimmering effect the MH has over the rippling water created by the powerheads. It looks very natural.

Mike

 

[ellisz]

20k MH's will give you a blue look like actinics. You would not be able to do a dusk/dawn effect with just MH bulbs though.

 

[scuba_steve]

or just go with 2 NO 03's due to they are cheaper and ya can have the dawn/dusk effect as well ! unless moneys not an issue go with 2 vhos with the new icecap ballasts with the dimmer have heard thats a real cool effect !!
but to save money yes ya could use the pc lights ya have now along with the mh

 

[Bearfan]

I was looking at that dimmer and thought that might be cool. This is still in the planning stage so money isn't an issue as of yet. I try to determine what I want, then how much it's going to cost.

 

[scuba_steve]

yea if moneys no issue the dimmers the way to do for sure

 

[Bearfan]

Money is only as big an issue as how small an issue I can convince my wife it is.

 

[scuba_steve]

heheh if shes like mine she will find a issue lol make sure you get her something real nice first it works

 

[klam]

I love the shimmer effect!

Sure it might cost a little more money in the summer to keep your pad cool but during the winter you will save a little money on heating.