Things to watch for when changing lighting?

[Son Of Skyline]

I'm thinking of swapping my 400w Radiums back to 250w Iwasakis for awhile to see if I can increase growth rates. Is there anything to watch out for, or little things to do to prevent any unforseen problems? Should I decrease my photoperiod an hour or so to acclimate the corals back to the higher lighting? Or am I just being paranoid and have nothing to worry about or nothing I need to change?

Thanks in advance!

[Namscam]

I think you should decrease your photoperiod and add like one hour or so every week to accilimate your corals. Maybe start of at like 6 hours....I dont know if it is necessary to do this because you are decreasin intensity since this is mostly done when intensity is increased, but i would do it just as a precaution

[Aquattro]

Mason, going to Iwasakis from Radiums will likely require some adjustment. Either raise the lights and slowly lower them, or provide layered screening that you can remove slowly (over a week should be enough).
Your BTA will also likely object and hide for a little while, so watch out for unwanted migration into pumps, etc.

[Son Of Skyline]

Mason, going to Iwasakis from Radiums will likely require some adjustment. Either raise the lights and slowly lower them, or provide layered screening that you can remove slowly (over a week should be enough).
Your BTA will also likely object and hide for a little while, so watch out for unwanted migration into pumps, etc.


Thanks Brad. Didn't realize the effect it might have on the btas. I'll watch out for them.

I can't move the bulbs up or down so I'll probably try to rig up some screening over the bulbs. Would simply reducing the photoperiod have the same effect?


Namscam, actually going to 250w Iwasakis from 400w Radiums in an increase in lighting. Although the Radiums use high wattage, they're actually not as bright as the 6500k Iwasaki :)

[Aquattro]

Also, reducing the photoperiod may not be enough. If the intensity levels cause too much photosynthesis in the short period, too much O2 can be produced within the tissues and damage can occur. Enzymes normally control this, but if O2 production is greater than enzyme response, you lose tissue and or zooxanthallae. Rigging the timer to go on and off every hour with an increase in the on period is a better way. the layered screen thing is good also.

[Namscam]

it may be brighter but i m talking about par value for intensity because dont 400w have higher par value than 250w

[Aquattro]

it may be brighter but i m talking about par value for intensity because dont 400w have higher par value than 250w

Sorry, you're wrong. A 250w Iwasaki has a lot more par than a 400w Radium.

[apepper]

If you look at the PAR of a 250W Iwasaki vs a 250W Radium on Joe Burgers MH test site you will see that the Iwasaki has about twice the PAR of the Radium for most ballasts. So a 400W radium is probably close to the 250W Iwasaki assuming you will get about 1.6 times the output extrapolating from the 250 Radium to the 400W Radium. The Iwasaki may still be higher with most ballasts.

http://www.cnidarianreef.com/

[Aquattro]

Sorry, the 400w radium on the HQI ballast had about 500 PAR, based on my system. Steve can confirm, but it may be lower. A Iwasaki on a HQI ballast reads 969 PAR, almost double a 400w Radium on comparable ballast. Even on the std. PFO, it measures over 700 PAR, still way above a HQI driven Radium. That radium was also 2 weeks old at time of testing. After a couple of months, the PAR was likely closer to 300.

[Son Of Skyline]

Sorry, the 400w radium on the HQI ballast had about 500 PAR, based on my system. Steve can confirm, but it may be lower. A Iwasaki on a HQI ballast reads 969 PAR, almost double a 400w Radium on comparable ballast. Even on the std. PFO, it measures over 700 PAR, still way above a HQI driven Radium. That radium was also 2 weeks old at time of testing. After a couple of months, the PAR was likely closer to 300.


Brad, are these numbers comparing the 250w Iwasaki vs the 400w Radium, or the 400w Iwasaki vs the 400w Radium?

[Aquattro]

Mason, this is the 250w iwasaki vs. the 400w radium. For the record, the 400w radium at 12" had a PAR of 343.09 , not the 500 I originally thought.

[apepper]

Wow, that's sure different from the results JB got with the 250W. He did his measurements at 8" not 12" but I would not have thought it would make such a difference. On the HQI ballast he measured a PAR of 403 for the 250W Radium.

[Aquattro]

There is a lot of difference based on distance and whether it is in water or not. Variables aside, I think we can pull from this the fact that a 250w Iwasaki is at least 50% more intense, PAR wise, than a 400w Radium.

So if you are swapping the more intense 250 for the less intense 400, you should take precautions to safeguard your corals! Agreed?

[Son Of Skyline]

So if you are swapping the more intense 250 for the less intense 400, you should take precautions to safeguard your corals! Agreed?


That's exactly what I was thinking. Although I didn't expect (but not surprised) that there would be up to a 50% difference between the two setups.

Thanks again Brad!

[EmilyB]

I am assuming that this is good news for me, as I was starting to worry a bit about putting 2 400w Radiums on my primarily softies/LPS reef. :confused:

[Aquattro]

I am assuming that this is good news for me, as I was starting to worry a bit about putting 2 400w Radiums on my primarily softies/LPS reef. :confused:

I think that would be fine Em

[BCOrchidGuy]

Brad, any thoughts on PAR value of a 10,000k Iwasaki 400w vs a 10,000 Iwasaki 250w? and how about Par value of a 250w 10,000k SA? And finally, what about Par Value on a 6500k 250w Iwasaki.

Thanks Doug

[Aquattro]

Brad, any thoughts on PAR value of a 10,000k Iwasaki 400w vs a 10,000 Iwasaki 250w? and how about Par value of a 250w 10,000k SA? And finally, what about Par Value on a 6500k 250w Iwasaki.

Thanks Doug

I don't recall iwasaki making 10k, so no thoughts there. I also don't think about SA bulbs or 65k Iwasakis, so nada again. Steve might have thoughts on it though. :razz:
Pretty much I don't think about PAR at all. I think my Ushio 10k are pretty and bright, same for my Radiums, but with more blue. I saw some info I knew was wrong in this thread and thought I should post what little I knew to help protect some corals from bleaching. That's all.

But Steve is gonna love this thread and I'm sure he'll answer all the questions above!! :biggrin:

[StirCrazy]

But Steve is gonna love this thread and I'm sure he'll answer all the questions above!! :biggrin:

oh where to start.. first if you are buying a system 400 watt rqadiums are a waist of time (unless you already have the ballast and don't want to change them.) radiums are a German bulb style which we all so commenly call HQI. the 400 watt bulbs had a starter added for the north american market but as Brad said they only put out 380ish PAR with a distance of 12" and 1/2 of that water. that would probably coralate to about 500ish by JB's test methods. the same ballast pushing 400 watt ushio bulbs on Brads tank put out 450ish PAR, on the same token the 250 watt radium pumped out over 550PAR on the same set up (6"air and 6" water) compared to the 380ish of the 400 watt.. now they both were run on a HQI ballast but sence we all know there is no such thing as a 400 watt HQI ballast the 400 watt was never driven to its full potential (and never will be unless someone figures outhow to make a german reactor ballast work in Canada :mrgreen: )

as for Iwasakis, yes they have a high PAR but they will not beat a 250 watt HQI ballast with a bulb like a radium or an AB on the ballast they are made for.

A good AB bulb on a 250 watt HQI ballast puts out around the same PAR as a 400 watt Iwasaki (mine was higher than 2 of the 4 I tested, the same as 1 and a little lower than the other)

now there were all kinds of factors to play with as I was doing thoes tests in different tanks so the turbidity could have been different as well as others.

(if anyone has 250 watt bulbs they arn't using at the moment and would be willing to lend them to me for PAR testing just msg me, I would like to test more than just the SA bulbs compared against a 2 year old AB (I already know the AB will have more PAR even at two years old, but I would like to see how they compare against other bulbs)

I don't have a regular 250 watt ballast but I am looking at getting 1 ballast of each type (if I can get them for cheep enuf) and setting it up in the garage so I can test any bulb. I am going to rig it up so all I have to do is use switches to select the ballast that will power a single test socket.

now as for the original question, I don't like any of the mentioned methods of aclimitating to new lights. I have three main reasons

1, moving the lights higher is not practicle for 80% of reefers,

2, using screens can be diffacult because if you get PVC ones they melt and the metal ones rust. Also you have to find a way to hold them in place,

and 3, shortening up the lighting period doesent work and usaly results in bleached corals.

what i recomend (and was recomended to me by Eric B) is to get a good timer and set your light cycles to turn on for 1 hour then off for one hour, then on for 1 hour and then off for one hour ect.. for the full 10 or 12 hours you would normaly run your lights. Do this for 2 or 3 days and change the times to on= 1hour 15 min off = 45min, a few days of this and then on = 1.5 hour off = 30 min, few days more then on = 1 hour 45 min off = 15 min. do 2 days of this then go to normal on for full cycle.

the reason this works is that a coral can handle 1 hour of intense light no problem befor it will reach it saturation point, then by turning the lights off for 1 hour its levels go down and it will be ready for the next blast. as this goes on the coral also develops protection from the more intense light so when you bump up the time on it will be able to handle it.

now I don't know the fancy terms of what kind of saturation level the coral will reach after 1 hour but I think i am getting a basic explanation accross.

Ok now Doug, this is the second time some one mentioned a 10000K iwasaki was that a typeo? just incase it wasn't I did a serch and didn't find any referance to Iwasaki making a 10000K bulb so to answer your question any of the other bulbs you mentioned are going to be higher PAR than a SA 10000K 250 watt.

Appeper, Joe's test was pretty good, i actualy injoied it but it has one serious flaw, it is through air only. why is this a problem you ask.. well think for a minuit air has no substance ad nothing to slow the light down or deminish its intensity other than distance its self, when i do my tests I try to do it in a situation that it would actualy be used in. i do it at a distance of 12" and I try to get 1/2 of that to be through water. the reason for this is that water affects different wave lengths differently, some colors it slows down more than others which can have little or maybe a dramatic effect on the PAR level of a bulb. it depends on which combanation of wave lengths they use to make 10000K. when I set up my test bench in the garage I am going to increase my testing distance to 24" (18" water aqnd 6" air) this will show actual penatration power even better.

Steve

[MitchM]

Steve, if you can manage it, and if your meters will read it, might I suggest you try to test the difference between still surface water and water with ripples? I've read where the water ripples can magnify the light reaching lower levels up to 15 times, in a pulse-like effect.

Mitch

[StirCrazy]

Steve, if you can manage it, and if your meters will read it, might I suggest you try to test the difference between still surface water and water with ripples? I've read where the water ripples can magnify the light reaching lower levels up to 15 times, in a pulse-like effect.

Mitch

that won't be hard concidering I can make the surface of my tank into a jicuzzi with the two tunze :mrgreen:

Steve

[Delphinus]

what i recomend (and was recomended to me by Eric B) is to get a good timer and set your light cycles to turn on for 1 hour then off for one hour, then on for 1 hour and then off for one hour ect.. for the full 10 or 12 hours you would normaly run your lights. Do this for 2 or 3 days and change the times to on= 1hour 15 min off = 45min, a few days of this and then on = 1.5 hour off = 30 min, few days more then on = 1 hour 45 min off = 15 min. do 2 days of this then go to normal on for full cycle.


Just wanted to add my comments from the peanut gallery. This method works very well.

[Son Of Skyline]

what i recomend (and was recomended to me by Eric B) is to get a good timer and set your light cycles to turn on for 1 hour then off for one hour, then on for 1 hour and then off for one hour ect.. for the full 10 or 12 hours you would normaly run your lights. Do this for 2 or 3 days and change the times to on= 1hour 15 min off = 45min, a few days of this and then on = 1.5 hour off = 30 min, few days more then on = 1 hour 45 min off = 15 min. do 2 days of this then go to normal on for full cycle.


Just wanted to add my comments from the peanut gallery. This method works very well.


Thanks guys. I'm going to try this method.

[One_Divided]

Mason, I would leave things as they are, you are getting fantastic growth and colour as is... I'd leave it and just make sure your parameters are all in the right place..

I am coming over sunday to wednesday.. I will be in town this time so we should get together.. see ya!



-Adam

[Son Of Skyline]

You may be right, but I do think that growth has started to slow in the past month. Maybe I'm just getting greedy :cool:

Gimme a call when you get in...and don't forget my table :smile:



Mason, I would leave things as they are, you are getting fantastic growth and colour as is... I'd leave it and just make sure your parameters are all in the right place..

I am coming over sunday to wednesday.. I will be in town this time so we should get together.. see ya!



-Adam

[JB NY]

Hi Steve,

There a few reasons the test was set up the way it was and not another way.

Measuring PAR values in tank is not the best way of measuring differences in lamps. First, the senor needs to be absolutely level, so you would need to set up a mechanism inside the tank to insure the sensor was kept level. Also, if the sensor is in the tank there is bound to be lots of things amplifying the light being read by the sensor. All reflectors are different, the shape of your tank and the angle of the light entering from where the sensor is, as well as stray light, all change the values. So the measurement you get in no way correlates to what someone else might find using the same lamp as you are testing. Lastly, water quality play a huge role in the amount of light actually hitting the sensor. Someone running a skimmerless system with no carbon would have much less light entering the tank as someone running carbon, skimming heavily and using ozone.

In the ocean higher wavelengths are filtered out as one goes deeper. But this doesn't translate well for lighting over our tanks. Wavelengths of around 550-575nm and lower (which is what most of the light on MH bulbs are) pass almost completely unobstructed in 1 meter of water. It's true that the higher wavelengths of over 575nm can be reduced by as much as 50% in 1 meter. But in the shallow tanks we use in aquariums a lot more of the light irradiated from the lamp is able to get through. Most of our tanks are just not deep enough.

The whole reason the test was done as it was, 8" from the arc tube of the lamp, in a flat black box with no reflector, was to get a reading that had as little variables as possible. Basically you should be able to take my lamp put in the same environment and read the same results. If I were to take a reading of my lamp over my tank and give you the same lamp, you would get a vastly different reading than I.

Personally I think measuring PAR values of the light a coral receives in tank would be a tremendous help to hobbyists. It would help when trading corals as well as when one is getting poor results with a coral another hobbyist is having great success with.

Sorry for the long post.

-Joe

[Aquattro]

Sorry for the long post.

-Joe

Joe, you're welcome to make long posts here as many times as you like. And it wasn't as long as Steve's anyhow! :razz:

Of course, we like new people to post lots of pics of their stuff, especially new frag tanks! :biggrin:

[StirCrazy]

JB, I loved your test and in no way was trying to slight it as it was very valuable information in my opinion. I was typing a lot and I should have worded it that in adition to the way you tested I want to do tests through water. so i will do both 24 inch of air and 25 inch (6" air and 18" water) the way I am going to avoid the problems you mention is i am going tu build a special testing cylinder to house the water in so my Apogee meter can be fixed in the bottom. this will be filled with clean tap water or fresh salt mix (I am going to try both to see if there is a difference due to the density difference, if there isn't I will use chlornated tap water for the test). by doing it this way I can rule out all the factors you mentioned.

the whole reason for wanting to do this is I found that the inverse square law doesent work when you add water to the situation. I don't expect large differences but I do expect that some bulbs will penatrate better than others.

Steve

[Doug]

:biggrin: WELCOME TO CANREEF, Joe. :biggrin:

[JB NY]

Thanks for the welcome! I guess I'll have to post some pictures of my tank now! :D

Heya Doug, thanks for the welcome too!

the whole reason for wanting to do this is I found that the inverse square law doesent work when you add water to the situation. I don't expect large differences but I do expect that some bulbs will penatrate better than others.

Steve, No problems, I just wanted to explain my side of the testing. I was getting a lot of heat earlier on and spent lots of time doing various tests and refining the process to satisfy as many questions and potential errors as I could.

I think the water definitely cuts off more light than air. Will be interesting to see what you find. Stray light and absorption will be the biggest factors to account for. Ideally you would want to set it up with no reflector, outside walls of the tank flat black, as well as the enclosure for the lights black as well. I would also either have 8" or 18" inches of air, not 6". That way you can at least compare your results before the water to mine or Sanjay's. There is definitely more to it than just PAR, spectrum without a doubt, plays a big role in the coloration and growth as well.

I wonder if glass reflects certain wavelengths back into the tank? If so, Acrylic might behave differently.

[BCOrchidGuy]

JB, water does cut out more light than air, water is 40 times more dense than air. Take a light reading 30 feet above sea level, one at sea level and one 30 feet below, for sure there will be a large difference between the other two and the one at 30 feet below.
Interesting thread, and TONS of information to absorb.

Doug

[StirCrazy]

I wonder if glass reflects certain wavelengths back into the tank? If so, Acrylic might behave differently.

I was thinking of making the test cylinder out of a 6" acrylic tube. as for readings at 8" I personaly think that is to close to obtain a totaly true reading with the apogee sencors, but that will be easy to do befor I do the water tests. this will give me a 8", a 12" and then a 24" using water. if I have the time maybe a 36" water test.

Steve

[JB NY]

so i will do both 24 inch of air and 25 inch (6" air and 18" water)

as for readings at 8" I personaly think that is to close to obtain a totaly true reading with the apogee sencors,

I'm confused, or maybe I was not clear. I did my reading at 8" from the bulb, so I'd like to see if you could do yours at this distance as well, before going into the water. You originally stated you were going to do it at 6", correct?

As for 8", it should be fine for the apogee sensor, I had two licor sensors I was able to check the apogee against at 8" from the lamp. The Apogee on average was only off around 2-3% from the Licor.

-Joe

[JB NY]

BTW are you using the sensor only, or do you have their meter for electronic lamps as well?

[StirCrazy]

when I said 6" I ment out of a total of 24" 6 would be air and 18 would be water.

I got the sensor (calibrated for electric light) and a digital multimeter that it is hooked to.

thats good the error ws that small, I have always done 12" as a base. I know the others are using smaller distances but 12" always seamed more realistic to me.

Steve