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.