PAR readings for general SPS reference

[kattz]

At the sand bed in a standard 90g tank, what should the PAR readings be at water surface, halfway down, and at sandbed for general SPS use?  LPS will be present as well.  I've read that if you set your tank up for 100 PAR at sandbed, you're on the right track.  Advice?  Opinions?

Thanks.

Kev

[cyberwollf]

i think 250-300 is was you want for most acro sps.  some LPS a little lower and 75 is about the minimum for  softies.  Thats off the top of my head might want to double check it.

[chromiumlux]

I hate to be the bearer of bad news fellas, but these par readings do not apply to led lighting. It is not par you are looking at when lighting your tank with led's. The correct measurment would be PUR. Right now it seems to be pretty much a guessing game as to where corals need to be placed under led lighting---MH techniques do not apply. It will also depend on the number of leds being used as to how high your fixture needs to be off the sandbed. This statement has been the kicker for me and, I as well as several others, are abiding by this as a safe means for coral placement.

"The PUR ratio is so high that ~50-60 PAR under the PR-25 is equal to ~150 PAR under a 14k halide bulb".

This applies to Orphek leds at 2w each. My leds hang approx 43" above my sand bed. I am still getting 120 PAR at sand bed. I know another reefer that is growing exquisite SPS corals under less than 100 PAR. And thes corals are growing like weeds. My point being that until we have available a means of measuring PUR that care should be taken in both placement and qty of leds used to light and grow corals.

[kattz]

Andy, as you know, this is the battle I'm fighting right now, which was the point I was making over at the other forum.  I can fry a frag in three days with the lighting ramped down to 50%.

[Learning_The_Hard_Way]

Do you have lens on your LED? I know this dramticallt effects the intensity.  I ran mine without them for a while and had good results.  Fireda few things when I out them back on.

[kattz]

Here's a good informative read:
http://www.americanaquariumproducts.com/Aquarium_Lighting.html

[cyberwollf]

I hate to be the bearer of bad news fellas, but these par readings do not apply to led lighting. It is not par you are looking at when lighting your tank with led's. The correct measurment would be PUR. Right now it seems to be pretty much a guessing game as to where corals need to be placed under led lighting---MH techniques do not apply. It will also depend on the number of leds being used as to how high your fixture needs to be off the sandbed. This statement has been the kicker for me and, I as well as several others, are abiding by this as a safe means for coral placement.

"The PUR ratio is so high that ~50-60 PAR under the PR-25 is equal to ~150 PAR under a 14k halide bulb".

This applies to Orphek leds at 2w each. My leds hang approx 43" above my sand bed. I am still getting 120 PAR at sand bed. I know another reefer that is growing exquisite SPS corals under less than 100 PAR. And thes corals are growing like weeds. My point being that until we have available a means of measuring PUR that care should be taken in both placement and qty of leds used to light and grow corals.

I have to admit I havent read up on PAR in a year or so, so I'm a little behind, but from my short googling just now, Im not convinced.  PUR appear to be the radation that can actually be absorbed by the Organism.  Which requires killing it to measure, and constantly changes as the zooanthelle adapts to your lighting conditions....

You have any links to scientific writups on it?  Sounds like an LED marketing scheme for low PAR, knock off LED makers to sell snake oil.  PAR is PAR.  Its the radiation in the right bands for photosythesis.  Links?

[chromiumlux]

Nope, no links. No scientific documentation. Just good old hands on personal experience. Just my observations on my own system since the employment of LED lighting. I think you misunderstood my point there Cyber. Do you run LED's on your tank? No snake oil here bud. Just awesome coral growth and coloration under 1/4 of what it would take with Halides. No doubt that PAR is PAR, no argument there. My LED system is a total of 225w. If I were to move this down to where a halide needs to be I would fry everything in my tank. This is what the issue is. Many people whom have either purchased LED fixtures or built their own have been misled in the old "more is better" scam. It takes far less LEDs to light a 90,150,375 gallon tank than to do it with Halides. Proof is in the pudding in my tank and several other tanks I have personally viewed with LED lighting.

[chromiumlux]

"Here is what I am discovering that is causing lower PAR readings and why you want lower readings."
"With MHs you are getting a wide arrangement of colors/wavelengths. Some you do not need or want. This causes the PAR readings to be higher."
"With LEDs we are able to pick the colors/wavelengths we want. We can leave out the colors/wavelengths we do not want or need."
"LEDs are just giving you more usable light so you do not need as big of PAR Readings as you would with MHs."

Summed up

[Wall_Tank]

It's not the amount of light that is burning the coral, it is the acclimation process.   I've not had a bleaching problem with my LED's.   300 watts of LED.   I'm sure less would work fine, I was just a little worried about coverage........and I couldn't go higher like Andy has done with his to get coverage.

[lazylivin]

I have been seeing a lot of threads like this lately regarding LED's.

First off great thread. Beautiful pics!

I wanted to chime in to share with you that I have also had amazing sucess growing sps under LEDs. I jumped on the LED wagon pretty early on with an early 20k Solaris fixture. I was so amazed at how well my corals grew under this fixture that I preorderd and waited months to recieve the I-IV model when it first came out. In fact, I bought two of them for my tank upgrade I was working on at the time. The I-IV was even more amazing. I ran it side by side with 400w MHs. I think my acros grew better under the LEDs than under the MH. My tank is 34" deep and my clams at the bottom did fine also. The colors of my corals were awesome. The fact that these fixtures hardly put off any heat made them even better. I can tell you from experience that LEDs can grow sps and grow them well.

That being said, I have to sadly say that I am no longer running them on my tank. Even though these LEDs started out as being equal to and maybe even better that MH, they just did not last. Somewhere about the time they were about 1 1/2 to 2 years old, it became very obvious that they were suddenly not doing so well. At first I thought it was an issue wth params or nutrients but the acros under the MHs were still doing just fine. I was sold on the fact that they would last 50,000 hours. It might be true that they will be still on, and maybe appear to be bright to look at, but what I have noticed is that they just won't grow anything. I changed out many LED bulbs that started dying after about a year, changed out fans that died, and power sources that died. I spent a ton of money on these fixtures so believe me I tried everything to keep them running. Working on them constantly got old really fast.

I finally gave up on them and replaced them with different lighting and my corals that were under these 2 year old LEDs now look alot better.

I definately know that LEDs have amazing potential but it will be a while before I will be brave enough to spend any more money on them.

FWIW I still have one I-IV LED fixture over a frag tank that's plumbed into my main system. I been able to cannibalize enough parts from three fixtures to make one work. It's going on 3+ years running now. It still appears bright but any acro I place in this tank turns brown and many won't even stay alive very long.(chalices still grow though) Acros sharing the same water, identical flow, but different lighting do just fine. It's like trying to grow sps under MH bulbs that haven't been change in two years.

I definately don't want to hijack your thread but is there anyone out there still having sucess groing sps with LEDs that are more that two years old?

[chromiumlux]

Come on Brian!!! Your killing me. Is that all you got to share on leds? I would have to rebute with the fact that solaris is old school tech, and yeah probably had issues, and as it is with my opinion, this is just another mans opinion. But at least he was a doer and not a scoffer....lol

[Wall_Tank]

Come on Brian!!! Your killing me. Is that all you got to share on leds? I would have to rebute with the fact that solaris is old school tech, and yeah probably had issues, and as it is with my opinion, this is just another mans opinion. But at least he was a doer and not a scoffer....lol

He may have posted........ but that is the question that all of us LED'ers are concerned with and going to try to answer.    "heat" is a killer of LED's.   The poster in that thread said he changed bad fans.    That could have very easily meant his fixture overheated.   That is one of the reasons I went with a DIY open heatsink design......in case a fan doesn't run it will hopefully get enough ambient air movement to keep the heat low enough.   I've really been considering adding a thermal switch that would kick off the LED's if the heat sink gets too hot.

[chromiumlux]

Thats a great idea. Besides, PFO Solaris was junk from the get go. Those units were ungodly expensive in 2008 and begain having issues not a month into operation.

[lazylivin]

Here is more Andy
1.) The LED systems do seem to bleach corals but that could be an acclimation thing or the lack of a broad spectrum of color focusing all the PAR in a narrow band that is un-natural to the coral which really just comes back to acclimation. Calling this PUR seems like a gimmic.
2.) Not to wild about the disco light look of white vs blue colors on the rocks. Maybe wider optics solves that problem.
3.) For larger systems the lack of heat requires additional heaters to keep the tank warm counteracting the electrical efficiency but smaller systems it could save even more money because chiller wouldn't be required
4.) Dawn to Dusk is awesome, dimming is awesome
5.) Total control over color
6.) Small and compact giving endless retro design options
7.) Very efficient giving higher PAR from less watts but this is always the case with the newest technology. Flouresent to VHO to Power Compact to MH to  T5 to LED to Plasma
8.) Ability  on some models to put the light where you want it in the tank
I could go on  but LED's are a great option and gives lots of new configurations for the reef tank hobby.
 

[kattz]

Paul/Andy:  Aren't your corals fairly lower (deeper) in the tank than what most would do if they were using MH technology?

[cyberwollf]

I think the original purpose of this thread was how much "light" is needed.  Andy, I'm not saying that LEDs are snake oil, If i had the cash I'd go that route.  What I am saying is there are knock off LED manufactors that could be playing up this unmeasurable "PUR". 

MH DO NOT cause inflated PAR readings, thats the whole point of PAR, it measures light ONLY in the spectrum used for photosytsis.

PAR will ALWAYS be greater than PUR.  You will have more AVAILABLE radiation than USEABLE radiation.  Law of conservation

There is no way that an LED (or any other fixture) can produce high PUR (unmeasurable) but low PAR.

Bottom line:  LEDs can put out the PAR and can grow corals great.  But i do think there are alot of slimy forgien companies that are playing up this PUR, while discounting PAR, Because they are using cheap knock off LEDs and charging premium.  Also, with good blue LEDs you can probably keep good color on corals for awhile without hitting them with enough PAR to reach photosaturation (thus allowing maxium nutrition via zooanthelle).  Stick to quality LEDs, manufacturers, check your PAR, and ensure you acclimate to the LEDs.  They can be very focused and you may get more of an average PAR reading while a coral is direcly in the "beam" of an LED and gets fried

Light is light, Photons are photons, radiation is radiation. 

[cyberwollf]

Ohh yeah, forgot to chime in 50,000 hour figure.  If you made you own fixture you are golden, you know what you are driving your LEDs at. BUT, if you once again buy a knock off fixture... whose to say they didnt buy the Q4 (lower binning) CREEs and are overdriving them to get the same brightness as Q5s.  You'd never know until 1.5 to 2 years later when you have burned through most of their useful life.

Once again, just be careful, there are many ways to screw people when they are willing to pay the price for new technology.

[Wall_Tank]

Paul/Andy:  Aren't your corals fairly lower (deeper) in the tank than what most would do if they were using MH technology?

Nope.   Never moved my corals.   I started my LED's with a max output of 50%, then moved their power up by 5% at 1 week intervals.  Now corals that I had mounted lower are doing better, because they are getting more light.

Your problem is probably more complex than just light.   Light/Alk/Lower nutrient.....   too sudden of a change of any of these can cause burned tips.

[chromiumlux]

Kev, I did lose a couple of corals at first. I have the option of raising my lighting instead of moving corals. I am currently using the old rule to start low and work up. I have adopted the technique of letting the coral tell me--through observation--where it wants to be. You can also do the screen acclimation technique, but I personally have never done this. I have a few acros on mounts on my sand bed that are growing and producing great color. Funny, that a lower par area of the tank suits some of my acros better. I have to agree with Wall tank that there could be several issues going on and not just the lighting. You could try lowering a few acros to see how they do. As far as salt is concerned, everyone has their preference and their budget. I personally have had great success with the ESV system and do not plan to change it. Back to basics would be to keep your system as close to natural seawater as possible. I am not sure about, nor do I have any experience with salts that are higher in this or that element. Hope you get this figured out and are able to stabilize your system.

[kattz]

We just went through my water at Lazy's house, and it's pretty much liquid sewage as far as nitrate level goes.  Also, I have a LOT of the same rock Andy had.  It's going out anyway with the sand change.

[HUNGER]

why are you going to get rid of the rock and sand  if you did that the tank will cyicle again

[chromiumlux]

Was that that Pukani stuff from RS? I just got done nuking mine and in the process of recuring.

[kattz]

Yep - bone white "wet" (not dry) Pukani from RS.  Have had it in here for months.  Have had problems for months.  If I were you, I'd toss it.  Mine will go out the door more than likely.

[Wall_Tank]

We just went through my water at Lazy's house, and it's pretty much liquid sewage as far as nitrate level goes.  Also, I have a LOT of the same rock Andy had.  It's going out anyway with the sand change.

So your test kits are bad too?  You were showing a Nitrate of 1.0

[kattz]

why are you going to get rid of the rock and sand  if you did that the tank will cyicle again

Dave, I never had any kind of cycle in my tank from day one.  Something, anything in the way of a cycle would be nice.  The Pukani is a possible source of issues and so is the sand.  In my case, more like parking lot gravel.

[HUNGER]

Well when u throw it out I will take it

[kattz]

Test kit wasn't bad, its just that I got the same reading that Lazy got, but my take on the instructions was different.

[kattz]

Well when u throw it out I will take it

The sand or the rock?

[HUNGER]

The sand or the rock?

both

[kattz]

I have one clean 5 gal bucket of white crushed coral.  Trade me for something?  The rock will go to Gerbers for a trade towards a kole or purple tang.  It's about 50 lbs.

[HUNGER]

i have a green chalice or a fresh cut wild acro

[kattz]

I'll hold the sand for you, Dave, it's yours.  We can talk about the trade later, as I just re-did the tank today and it's gonna take a day for it to warm up.

[HUNGER]

cool

[DarinSchmidt]

Bottom line:  LEDs can put out the PAR and can grow corals great.  But i do think there are alot of slimy forgien companies that are playing up this PUR, while discounting PAR, Because they are using cheap knock off LEDs and charging premium.  Also, with good blue LEDs you can probably keep good color on corals for awhile without hitting them with enough PAR to reach photosaturation (thus allowing maxium nutrition via zooanthelle).  Stick to quality LEDs, manufacturers, check your PAR, and ensure you acclimate to the LEDs.  They can be very focused and you may get more of an average PAR reading while a coral is direcly in the "beam" of an LED and gets fried

Light is light, Photons are photons, radiation is radiation.

I agree 100%. Orphek is discrediting PAR mainly because the LEDs they are using are their own, "specially formulated". Building up some Hype over nothing. So they need to find a way to sucker someone into buying their $900 60 led system. Though their system is mainly desined for deep waters.

My corals have been happy at 250-300 PAR, when i ramped them up to 350, they werent too happy 3 days later.

[Reefpete]

I agree 100%. Orphek is discrediting PAR mainly because the LEDs they are using are their own, "specially formulated". Building up some Hype over nothing. So they need to find a way to sucker someone into buying their $900 60 led system. Though their system is mainly desined for deep waters.

My corals have been happy at 250-300 PAR, when i ramped them up to 350, they werent too happy 3 days later.

That's why I am putting my money on your design/hard work as far as LED's go! I haven't personally looked at your set up but from what I have seen it the best design around for the money

[harleyrider]

Myself and Chromulux, (Andy) both run Orphak and up to my old Led's they are second to none!!.  A little pricey but what isnt in this hobby, you get what you pay for!!

[Reefpete]

Myself and Chromulux, (Andy) both run Orphak and up to my old Led's they are second to none!!.  A little pricey but what isnt in this hobby, you get what you pay for!!

How long have you had them?