Par is generally considered from 400 to 700nm. Actinic is 420 and still within the range of PAR.

This graph is for land based plants but it kinda gives you an idea of which colors are utalized the most.

[IMG]http://reefcentral.com/gallery/data/500/38553Plant-Human-Eye-Response_01.jpg[/IMG]

I figure everything would be shifted towards the blue end for corals and continue moving towards blue the deeper the coral was in the water. I figure acros and other shallow water corals should have quite a bit of red and yellow light. One thing to keep in mind is the 20K halide only puts out about 40 to 50% of the PAR a 10K does. It would be interesting to do a long term experiment running 20K 250's with 10K 150's to see what happens. You wouldn't have to worry about burning the corals with too much red and yellow from the 150's and the 250's would provide plenty of blue light for coloring.

Care to elaborate...dont get what you mean...

You said it wasn't all about PAR and your 20K lamps don't cause corals to brown out like a 10K does. The point I was trying to make is that blue light is still in the PAR spectrum so it is about PAR but perhaps more focus should be placed on quality rather than quantity. I was sorta agreeing with what you came up with but wondered if your corals did better because of the different spectrum of light or because it wasn't nearly as intense as the 10K's.

sorry, I meant to direct my question to Reefvet...dont worry Grim, you and I are on the same page otherwise...I just didnt get what vet said.

I wonder what Sanjay might think...

[QUOTE][i]Originally posted by Herbert T. Kornfeld [/i]
[B]Care to elaborate...dont get what you mean... [/B][/QUOTE]

Corals are highly adaptive, look at the wide range of morphs a given acro can grow into depending on the environment it's in. Water quality, current, ORP, calcium, just a few of the many factors involved in color and form in my experience.

I've grown corals under 6.5K Iwasakis that had more blue and green than identical frags grown by friends under VHO actinics and 20Ks.

PAR is such a small part of the equation.

But a 6.5 Iwakawi is a PAR monster. I agree that the corals can adapt to different colors over time but they do need a certain degree of light to survive.

Doing different searches, it seemed to me that the Reef Fanantic ballast kicked butt.

isnt that just another electronic though? I would just go HQI on just about everything these days...uless you have a really blue bulb that you are looking to preserve (like a xde or radium).

Kinda agree Herbert but doesn't HQI shorten SE bulb life?

So what's the big advantage of an eballast (Icecap) over a PFO HQI ballast? I'm still confused and have already bought one Icecap 250. I'm contemplating getting rid of it looking at the PPFD values on Sanjay's site. PFO blows it away with any bulb.

[QUOTE][i]Originally posted by Herbert T. Kornfeld [/i]
[B] I would just go HQI on just about everything these days...uless you have a really blue bulb that you are looking to preserve (like a xde or radium). [/B][/QUOTE]

Depends on what you are trying to accomplish. HQI's shorten bulb lifespan, as you mentioned. They also suck up more electricity and burn a lot hotter than other ballasts. I've ran HQI's for the past 3 years but will soon be "downgrading" to electronics.

I feel that with the better reflectors of today, "downgrading" to electronic is not much of an impact. Especially since you can also counteract the effect of slightly lower less output by bringing the lights just a little closer to the water. That is the nice thing about knowing the numbers. :-).

There is still illusive issue of lamp life, may be someday we can put it to rest.

As for the heat issue, you have to realize that energy in has to equal energy out. There is only a small % of energy that is being converted to light (25-30% or even less). The rest has to come out in some other form. Magnetic ballasts put it out as heat.. the electronic tend to put quite a bit out as electromagnetic waves hence the stories of EM interference with X10, TV reception etc.

Even the light that does not get used up for photsythesis eventually ends up as heat. So really for most practial purposes Watts IN = Heat OUT

My advice to most people is that unless its really not working for you (and you know its the cause), don't change anything.


sanjay.

I like HQI in most cases, esp if you are going for the most output you can get (prolly paired with a 10,000K bulb then). In cases where I am looking to preserve a bulb that might otherwise color-shift or expire quicker on a HQI ballast (read: some 20,000Ks and radiums), then an electronic comes in handy. I can run Radiums for a year on an electronic ballast and they dont seem to color shift much...cant say the same for a HQI...6 months and the sucker is dead. Also, the radium just looks bluer on the icecap.

Something I found interesting...When I swapped out my 10,000K ABs recently for all pheonix 14,000Ks, I compared the 10,000Ks side by side with a new 10,000K. I found that the 10,000Ks on the HQI ballasts were very similar to an original output after a year of running, but with the icecap powered 10,000K, the bulbs were duller, and had color shifted more. I found this odd when I tested one, but after two, this cant be just a defective bulb x2. Is it possible for a 10,000K to last shorter on a icecap than a HQI? IME, it seems so.

I have a Q Sanjay. I have a problem with removing 250wattDE bulbs. I use PFO pendants, and these buggers just wont come out w/o a big fight. I was lucky this last time, as I only broke one bulb trying to remove it. Is there a trick that I should know? Figure I should ask you since you prolly have to do this more than anyone... You should see the inside reflectors on some of these pendants...all dented and bent behind the bulbs from my knuckles as I try to pry those buggers out. It seriously is one of my least favorite chores...whats the secret to getting a 250wattDE out of a PFO pendant?

what if you loosen the screws on the sockets, would that make it easier to get them out?

Herbert T

Are you saying you tested a lamp that ran a year on an Ice Cap and one that was ran a year on HQI, OR you had 2 lamps you ran a year and tested one on an Ice Cap and 1 on a HQI?

I haven't tried this yet but for removing the 250's I was thinking something like a crochet hook to pry the lamps out.

I have 4 250wattHQI lamps....2 on HQI, 2 on icecaps...paired up on 2 tanks. I removed one lamp from each and put in a new 10,000K to see how much of a difference there would be after burning for a year vs. a brand new one. The results prompted me to then put back in the bulb I had just taken out, and put the new bulb on the other ballast by swapping ballast plugs (to see if both bulbs had the same result both times). The bulbs run on the icecaps for 1 year had a different spectrum than brand new, and the ones run on the HQI had not changed as much. Im beginning to think that if a bulb is designed to run on HQI, run it on HQI! If its designed to run on magnetic, only then is electronic a suitable substitute...just an observation.

As for getting the bulbs out...I did resort to bending a wire behind and around the lamp at each end where the glass meets ceramic, and then pulling the wires...but while this did not dent the reflector like my hand did, and required much less force...the bulb broke because all of the force applied to such a small area.

There has to be an easier way....

Interesting. Maybe mark those lamps and send them to Sanjay so he can measure the spectrum. That would be interesting to know.

All I know is that since I went to the pheonix 14,000Ks, my red flatworm population has vanished. They must prefer light from a lower spectrum or something.

Oh, and make that 2 lamps that died when I took them out of PFO fixtures...just saw a crack on the other one's base today. I could send them to Sanjay...well, one at least...the other one lost its ceramic on one side.

They could probably still be lite with no ceramic.

You think aquarium lamps are harsh. The lamp on the big screen TV went out today. About 300 buck with shipping for a new one.

With more usable PPFD on unsheilded setup, I was thinking of removing the glass lense my Reef Optix pendant. Has anyone tried running it this way? If so, will small amount of water splashes cause the bulb to break?

its a SE bulb I take it???

Double Ended actually, that's why I am unsure.

Removing the glass with DE bulbs is not an option. It is needed to block UV. Without it, your tank will be UV'ed and it could also hurt your eyes.

Herbert is right. DE bulbs do not have a UV shield around them so they require a glass lens to filter out the harmful uv rays. SE bulbs have a uv filtering outer envelope already built in so you don't need to run a lens with them.

[QUOTE][i]Originally posted by Herbert T. Kornfeld [/i]
[B]
Something I found interesting...When I swapped out my 10,000K ABs recently for all pheonix 14,000Ks, I compared the 10,000Ks side by side with a new 10,000K. I found that the 10,000Ks on the HQI ballasts were very similar to an original output after a year of running, but with the icecap powered 10,000K, the bulbs were duller, and had color shifted more. I found this odd when I tested one, but after two, this cant be just a defective bulb x2. Is it possible for a 10,000K to last shorter on a icecap than a HQI? IME, it seems so.

I have a Q Sanjay. I have a problem with removing 250wattDE bulbs. I use PFO pendants, and these buggers just wont come out w/o a big fight. I was lucky this last time, as I only broke one bulb trying to remove it. Is there a trick that I should know? Figure I should ask you since you prolly have to do this more than anyone... You should see the inside reflectors on some of these pendants...all dented and bent behind the bulbs from my knuckles as I try to pry those buggers out. It seriously is one of my least favorite chores...whats the secret to getting a 250wattDE out of a PFO pendant? [/B][/QUOTE]

You want to see my collection of lamps with the ceramic ends broken off :( and my collection of broken of holders, and cuts on my hand . I find that some of the Chinese lamps are the worst. May be the ceramic is not baked well enough or not the right mix, some just crumble with a little bit of force. I have found that loosening the sockets from the housing helps a bit. Creating that little bit of play helps accomodate the variation in the lamps a little better.

I would be very interested in testing your hypothesis that the HQI actually increased lamp life (or vice versa), so send me the lamps.

sanjay.