power usage mh vs. power compact
 

would the electric bill alone validate staying with power compacts? Is there another benefit to the metal halides other then the cheap bulbs?

IMO.....great growth of pretty much anything.

I have 2 power compacts each with 4 65 watt bulbs thats 520 watts out of the power compacts for my 75gallon tank. So are you saying that 2 400watt metal halides and the extra electric bill is worth the difference? I am trying to decide what to do because my bulbs need to be replaced I had one burn out on me.

400W is overkill :)

2x250W would be fine for that tank.

I have 2X250 Over my 58, there is no way 400w is overkill. If can afford it, get it! Just remember you will also have to deal with the heat and electric bill that comes with it. What are you keeping? What do you plan on keeping? How deep is the tank? More specifics would surely help us help you.

If you are a responsible reef keeper you have to buy what is BEST for your animals. If you are keeping SPS and clams, yes, MH over PC anyday. Softies and sum LPS high in the tank, no, stay with PCs, be fare to the animals and don't CHEAP OUT!

I dont really have anything yet I just have a few fish and one anenome. But I want to be able to get whatever I want in there so that is why I am looking. It is a standard 75g tank so the tank is 21in tall and prolly only 18 to the sand bed. currently there are 2pc each with 4 65w bulbs.
So everyone is saying mh is better the pc I believe just more expensive to keep.
so do I need 2 400 watt or 2 250?
what color temp is best?

if you need more tripstank let me know I will post it I am really trying to get as much help as I can making this decision so that I make the right one being it is so important for the tank. Thanks.

also, pc bulbs don't last quite as long as MH bulbs, so you will be spending more in the long run on bulbs with pc

Re: power usage mh vs. power compact
 

Simple, Metal halides put out from 2 to 3 times the usable light per watt as PCs.

A single 175w MH would put out more light than your PCs.

I've got basically the same setup as you Trips, adn I disagree.. my 2x250 on my 58 is most certainly overkill. (unless you meant for there to be a comma in there, and you're agreeing with me).

Honestly, 2x175 is more than enough on that size tank.

My vote would be for 2x250W bulbs. If you want mad growth, put some quality 10k bulbs in there and supplement with T5 actinics or blue+ bulbs. If you want good growth at lower electricity usage, just use 14k MH bulbs such as Hamiltons or Ushios and don't run actinics.

I personally love my 250's! Fast growth, great colors, and depth penetration. But the debate is not over how many watts of MH, just if they are better than PCs in accordance with the price of electricity. Putting my setup and everyone elses suggestions aside, I still vote for MHs over Pcs.

Ohh yeah, but to comment, I have XM 20,000Ks on my 250s and it looks great! I have SPS and Clams on the sanded and don't have to lose sleep over their health.

Ok, that makes sense. I still think you could run 2x175 20Ks, and be fine though.

I run 2x250 10ks, and its serious "burning stylo on my sandbed" type overkill

Like the saying goes, you get what you pay for.

ok so 2 250w mh bulbs seems to be what everyone is saying. The 1400 does sound good I may want to put an actinic on there on my own just for the color?
sounds like the xm bulbs are popular is that what you all recomend?
Is a coil core ballast ok or is there a performance difference other then the startup time?
Last question on this topic 2x250w mh would be cheaper then my 520w pc right now to run and buy right?

electronic ballasts will cost more up front, but are more efficient than magnetic ballasts, which means they'll be easier on the electric bill

ahh so prolly a better way to go in the long run, especially since I dont want to see my elec bill go up 30 bucks a month like my dad did.

T-5's

Two 400 watts will bew an overkill on that tank, Two 250 watts is more than enough to keep watever you need including sps and clams.
If you are not using actinic supplementation I would recomend 14K bulbs.
Watt per watt you will not be increasing your electric bill but you will increase the light output.
You can explore using four of the existing 65 watters with actinic PCs for supplementation in which case I would recommend 10K for the halides.
Including conversion losses right now you are using about 580 watts vs about 560 using two 250 watters, if you use 4 additional 65 watters for supplementation you will increase consumption to about 850 watts or an increase of 270 watts over what you use today.
Assuming you have the lights on 10 hours and that your power cost is 7 cents per kilowatt-hour that will be an increase of 82.13 kilowatt-hours per month or $5.75 additional per month in your power bill.

wow what a great answere! Thank you for all that info.
So if I understand correctly you are saying the best situatoin would be to put actinics in my current pc and then get 10000k metal halides? 2 metal halides and 4 bulbs of actinic lights sounds like an awful lot of light?

5 dollars a month is way worth it I was worried about 30 which is what I heard from my dad with what he did but he could have changed some other things too and not told me.

Yes you can use the MH alone at 14K or MH with the PC as actinics. Using the actinics gives you the additional option of simulating rise and dawn by turning them on before and off after the actinics. You can use 10K and leave the actinics on while the MH are on (Power will be OK as actinics do not put out great intensity or you can use 14K with the actinics and turn the actinics off when the MH turn on but this last option require a timer that can turn the actinics on and off twice in the day.

You have to look at your electric cost first. His calculations are for $.07/kwh.

I pay $.19/kwh, so my changes would be $12-15 a month.


Honestly, if you're gonna run 10K bulbs, run 175s. I run 2x250 on my 58, and I burn the crap out of everything. If you're going to run 20Ks or 14Ks, fine, but 250w 10ks can handle quite a deep tank.

Yes, Rich is right, Power rate changes by region and sometimes even by location, I used the power rate most likely to be foun in the Mid West while in places like California it is higher.

Using 175 watt MH is also an option if you are to use the actinics. You can locate the sps in the higher areas of the rockwork while LPS can be located toward the sides and bottom giving the aquarium more diversity.

I would say 2x175W is good enough. 2x250W is OK, but 400 is definitely overkill. I use 10K 175W MH on my 75 (20" deep) and I'm having difficulties in keeping soft corals and mushrooms (as Rich said: "I burn the crap out of everything"). I do have light-loving SPS and a crocea clam in my tank. I place them in the upper portion and they're doing abosultely OK. So, if you want to keep a mix of softies, LPS, SPS, and clams, I say 175s with actinics are good enough and also fairly fleasible. If you want to keep mainly SPS and clams, then 250s are the way to go.

ok well I am in the midwest and am relocating to the middle of nowhere fargo next week so I am sure I will be at the lower number anyway.

I am confused as far as what bulbs now though are you saying that 2x250 are too much light? or only with the actinics? I think simulating a sunrise option is cool and I have the actinic's and pc already so this option would be easy to do? What is the best situation for the fish and coral? would 10000 and actinics be better then the 14000? or 2 175 instead of 2 250? I have 2 timers already.

2 250 watters on 10 K might be too much if you plan to have other than sps and clams 2 250 14 or 20 K (without actinics) will be OK for a mixed tank as the higher the Kelvin normally there is lower light intensity (PAR).
In general for flexibility in the kind of tank you would like to have (It is always nice to mix some mushrooms and wavy LPS corals) you will be better off with the actinics and two 175 watters 10 K
The other advantage is that with that combination lowers your increase in power consumption.

Its not that the actinics are too much par, its the 2x250 10Ks that are pushing it. Run 2x14Ks with actinics if you want. 2x10Ks are just a TON of light though.

so 2x175 10000 with actinic. or 2x14k which is better? is it just preference? I have always had the 10k in my pc so I am not sure what reason there would be for changing?

10K metal halide without supplementation might be on the white yellow for your likeing, in addition on shallower tanks the blue range of the spectrum better simulates the light spectrum at deeper water. So you can go with 10K plus actinics to fill in the blue spectrum gap left by 10K or use 14K or 20K which already contain a higher portion of blue spectrum.
In general corals under 10 K grow faster but turn pale compared with corals under 14K and 20K which grow slower but with deeper coloration. A combination of 10K (intensity adjusted not to exceed the requirment of PAR) plus actinics is also a means to try get the good of both worlds.
In addition actinics increase the fluorecense of some species, specially the red and greens that can really glow.

well who doesnt want color? so from what you said I am taking 2 250 watt 14k with my pc with actinics for sunrise and sunset? Is that the best possible situation without adding more lighting?

Do you think i will need 175 14k or 250 14k
the actinics would just be sunrise and sunset unless you think I would need more I could always mess with one set on one off and see how it changes the color too.

My specific proposal would be 2 175 watt MH 10K plus 4 65w PC actinics for supplementation and rise and dawn effect.
Who else vote for this? :D

alright well thats cheaper I think too and I have the bulbs I would be using old actinics but between the 4 that should do wouldnt you think. I think 2 are 6 months old and 2 are a little over a year.

what 10k bulb is best? under 100 preferably the 50=70 a piece would be best? and what ballast?

Are you sure 2x175 is enough? I keep hearing people talk about 400 watt bulbs and much larger setups?

I also vote for the "2x175W 10K plus actinics".

Forget about how other people are tallking about 400W bulbs. It's all about your own interest. Again, if you don't have a deep tank (> 24") and you want to keep mainly LPS and softies (with a few SPS or clams), then you have no strong reason to use the powerful beasts.

I started my 225 gal tank 30" deep with 175's, later one I got the hipe and switched to 400w and I am still trying to lower the intensity, rised the hood, changed to 20K's and still too much.
The best 10K performance wise I ever had is the Ushio although some people complain it is not white enough. XMs are also one of the most popular and cheaper.
Ballast wise I am biased toward electronic ballasts for the flexibility they provide in selection of any type of bulb (Pulse or probe) and because of the low heat generation and less weight, For 175 either Hamiltons (made by Advance) or IceCaps will be my choice.
If you go for magnetics you need to select the bulb first as different bulbs may require different ballast types.
On your used PCs I will keep the 6 Mo. old but the one year olds are due for replacement, you do not notice how deteriorated they become until you replace them.

sounds great I will go with the 2 x175 10000k and probably ice cap ballasts thank you for all the help!

:thumbsup:

For a 75g community tank with mostly LPS/Softies and a few sps/acropora, 175Wers will be fine. However, when you start getting seriously into SPS /Acropora, 175W may work but most likely your corals are not going to get the intensity to really show them off. I've had pretty much all MH over the years from 150W single ended up to 400w including the double ended ( except for 400W de ). I can definately say without question that some of your SPS/Acropora currently under 175W that you think look good now will change some much ( mostly for the better ) under higher wattage MH that you won't even recognize the coral.

Whenever you want to step up to higher K bulbs, you really need the higher wattage MH to help compensate for the intensity loss. So if your ever considering higher than 10K bulbs best to step up in wattage. Also, higher K bulbs tend to be more friendly with LPS/Softies so you can still keep them without any major issues when using higher K bulb. So no 250W or 400W is not too much when dealing with higher K bulbs. Definately if sticking with 10K bulbs there is a trade off between acropora improvements and detriment to some LPS/softies.

Unfortanately, the original thread owner really doens't know what he/she wants or just how serious into Acropora they find themselves getting into years from now as reefkeeping experience grows. There are quite a few tradeoffs and no one lighting solution is a catch all for everything as the thread owner is looking for. If there was, we all would have it wound't we.....;)
But from my 11 years of experience with Mh goes, If I had to pick one bulb that is most friendly with a wide variety of corals from the most demanding acropora down do low light LPS/softies, it would be the 400W 20K XMs ( and/or Radiums ) providing heat and electricity is a non-issue.

heat isnt an issue I am getting a chiller and elec. seems not to be an issue since it is not near as bad as I thought it was going to be. If I go to a higher k bulb I would go up in watts as stated earlier. Thanks for the help guys.