Why so resistant to getting PAR numbers???

[Dana Riddle]

I'd be a lot more interested in PAR at $200. Which one do you recommend?

Look at Apogee Instruments' website - they have a number of PAR sensors starting at $184. I don't know which one is right for your situation.

 

[chipmunkofdoom2]

The question is - is that estimate going to be any more accurate than I can get watching BRS's videos where they test the PAR of my light at various heights and positions? Or the threads where Dana has tested a whole bunch of other lights? Etc?

Yes, it absolutely will be more accurate. BRS, Dana and the reefing community don't test every single permutation of every single light there possibly is. Your own measurement will be better if you want to, say, run the lights closer to your tank.

Or farther away.

Or use more units.

Or use fewer units.

Or use a custom color setting for LEDs.

Or buy a new, novel combination of T5 bulbs.

Or use a different generation of LED light.

Or add supplemental LEDs/T5s to your existing lighting.

Or change MH bulbs or ballasts.

Or buy a brand new black box that nobody has tested.

Or buy a black box from the same manufacturer, but the LED layout has changed.

Or change lights and want to make sure the new one roughly matches the old one in intensity.

Or any other thing that could potentially alter the intensity of your light.

If you don't want to measure your own PAR, that's fine. Nobody's going to come to your door and put a gun to your head and force you to measure it. I'm not going to advocate ignorance and laziness when it's so cheap and easy to get a reasonable PAR estimate. It literally will take less than 20 minutes and less than $20. Skim over Dana's article in my previous post. Go to Amazon, search for lux meters and buy one. When it arrives at your house, hold it over your tank, and divide the reading by 45 to 70, depending on the lighting technology. That's it.

 

[StlSalt]

Thanks guys. I just look

Black Friday is coming up.
I got the USB Smart Quantum SQ-420 PAR Sensor - Apogee that plugs into my laptop for $190 last Black Friday

Thanks to everybody. I hadn't looked at the SQ-420 for awhile BRS has it for $234 last time I looked I think they were $350. I'll see if I can hold out for a better Black Friday deal.

 

[92Miata]

Yes, it absolutely will be more accurate. BRS, Dana and the reefing community don't test every single permutation of every single light there possibly is. Your own measurement will be better if you want to, say, run the lights closer to your tank.

Or farther away.

Or use more units.

Or use fewer units.

Or use a custom color setting for LEDs.

Or buy a new, novel combination of T5 bulbs.

Or use a different generation of LED light.

Or add supplemental LEDs/T5s to your existing lighting.

Or change MH bulbs or ballasts.

Or buy a brand new black box that nobody has tested.

Or buy a black box from the same manufacturer, but the LED layout has changed.

Or change lights and want to make sure the new one roughly matches the old one in intensity.

Or any other thing that could potentially alter the intensity of your light.

If you don't want to measure your own PAR, that's fine. Nobody's going to come to your door and put a gun to your head and force you to measure it. I'm not going to advocate ignorance and laziness when it's so cheap and easy to get a reasonable PAR estimate. It literally will take less than 20 minutes and less than $20. Skim over Dana's article in my previous post. Go to Amazon, search for lux meters and buy one. When it arrives at your house, hold it over your tank, and divide the reading by 45 to 70, depending on the lighting technology. That's it.

Accurate *to the point that it actually matters* is the question.

What is the error range when converting a $20 lux sensor to par with LED fixtures? Do you know? If its more than 5-6%, then we're back to the point where I need to eyeball corals and figure out where they need to be - so it hasn't gained me anything.

And frankly - once you've got a handful of corals in the tank - its pretty easy to tell which areas can keep what.

Its not ignorant or laziness - its the fact that knowing I'm at 286 instead of 250-300 doesn't tell me anything that's actuality useful.

 

[Ebisan]

I think a PAR is crucial. I paid the price for not measuring my PAR before switching from MHs to LEDs. I built one with an Apogee sensor and a cheap multimeter. Have to multiply the reading by 5 to get the PAR reading but it has been working great.

 

[mike550]

I rented a PAR meter (and yes -- put down the big bucks deposit), and would easily do it again. As others have pointed out, there are a lot of variables to successfully managing corals -- so why wouldn't you want to know your PAR since lighting is a key variable.

To be clear, when I used the PAR meter I was not focused on scientific precision or quality of the light spectrum. My use of the PAR meter was really to get a sense of PAR intensity at different levels and locations in my tank (80 at the sand bed, 120-150 around the mid-level, 250-300 at the top of the rocks on the right side, etc.). What I learned was very surprising, and what looked "bright" to me was in fact much lower PAR than I expected. It also helps guide my coral placement. The benefit to this is that I won't rent a PAR meter again unless / until I change my lights.

I would also say that BRS and others do a nice job reviewing lights and offering a PAR analysis based on their setups. So while not perfect, it gives you a sense of direction.

 

[cshouston]

PAR is only a small part of the equation. There are many other things like spectrum that also play a part. Also LUX and PUR. The clarity of your water also plays a huge part. If a grows out and shades another one it can affect the PAR. i have never tested my PAR levels and I never plan on it. Place a coral where you think it will do good and watch it. If happy and growing don't change. If unhappy then move. Lights also lose strength over time, which will also affect the PAR. IMHO PAR is a waste of money and time. It is but a tiny part of a successful reef tank. Much like ORP. Knowing the value can help, but neither is a huge factor in success vs failure.

out of curiosity, do you glue down your corals then snap them off if they aren’t happy? I don’t really have enough holes and crags to hold all my plugs. Right now, everything is just on a magnetic rack, but I was planning to start gluing soon.

 

[SMSREEF]

Its pretty amazing what our eyes can see vs what the PAR actually is when measured.

One question I have for @Dana Riddle ...
How accurate is the Apogee USB Smart Quantum SQ-420 PAR Sensor in measuring PAR of LEDs? I run Hydra 26's with high Blue, Royal Blue, UV, Violet, medium white so tank doesn't look blue, and low red and green. Not sure the colors make a difference but thought I would throw them in just in case UV or blues matter.

 

[Ippyroy]

out of curiosity, do you glue down your corals then snap them off if they aren’t happy? I don’t really have enough holes and crags to hold all my plugs. Right now, everything is just on a magnetic rack, but I was planning to start gluing soon.

I used a rack and moved them up slowly. Then I just set them in place. If they fall I glue them down. After a few weeks I will use putty and make them permanent. They snap off easily with glue.

 

[ScubaFish802]

Black Friday is coming up.
I got the USB Smart Quantum SQ-420 PAR Sensor - Apogee that plugs into my laptop for $190 last Black Friday

Look at Apogee Instruments' website - they have a number of PAR sensors starting at $184. I don't know which one is right for your situation.

Awesome recommendations, added to the black Friday list. For the cost of 2-3 rentals/uses I would happily pay 200 for my own par meter. That should pay for itself at some point + then the only person who is responsible for shipping is the seller.

 

[MERKEY]

out of curiosity, do you glue down your corals then snap them off if they aren’t happy? I don’t really have enough holes and crags to hold all my plugs. Right now, everything is just on a magnetic rack, but I was planning to start gluing soon.

PAR is only a small part of the equation. There are many other things like spectrum that also play a part. Also LUX and PUR. The clarity of your water also plays a huge part. If a grows out and shades another one it can affect the PAR. i have never tested my PAR levels and I never plan on it. Place a coral where you think it will do good and watch it. If happy and growing don't change. If unhappy then move. Lights also lose strength over time, which will also affect the PAR. IMHO PAR is a waste of money and time. It is but a tiny part of a successful reef tank. Much like ORP. Knowing the value can help, but neither is a huge factor in success vs failure.

The problem with this is when you purchase coral at higher prices and want them to look the same under the same lights and have similar growth and health you need to know par. This can be very risky for reefers to just throw coral where ever and hope for the best. I'm not saying it isn't working for you but it is a gamble for sure.

Lets say you purchase an acro that grow at 500-700 par like purchased in these most recent live sales, and you put that coral at 200 PAR not only will you not see the same color or the same growth.

PAR is important when the reef calls for it.

 

[Vette67]

In the case of Metal Halide, I don't know what it changes. It would strictly be a curiosity thing for me. If someone let me borrow a PAR meter, I'd be curious to know what numbers I'm getting. But aside from curiosity, it serves me no benefit. I can't dim my lights, or turn up the "blues" or anything else. My controller is an on / off switch. That is about it. And unless I build a new hood (mine is out of 1/2" oak plywood, so it isn't cheap), then my lights are not moving anywhere, and haven't moved in almost 20 years. So in the case of LED's where you can control output, I can see a distinct benefit. But when PAR is fixed and almost not controllable, there is little benefit to justify the cost. It would be a nice conversation piece, that's all.

 

[92Miata]

The problem with this is when you purchase coral at higher prices and want them to look the same under the same lights and have similar growth and health you need to know par. This can be very risky for reefers to just throw coral where ever and hope for the best. I'm not saying it isn't working for you but it is a gamble for sure.

Lets say you purchase an acro that grow at 500-700 par like purchased in these most recent live sales, and you put that coral at 200 PAR not only will you not see the same color or the same growth.

PAR is important when the reef calls for it.

There's no such thing as "the same lights" - because PAR, phosphates, nitrates, alkalinity are all interconnected and all relevant to color and health. If you take a coral at 700 par in a tank with .25ppm phosphates/50 ppm nitrates and put it in a tank at 700 par and .02ppm phosphates/1ppm nitrates - you'll nuke the thing.

So that actual par number ends up not being that useful - you end up having to put it lower than you'd like and work it up - because too low light is always better than too high.

Its useful knowing where the 'hot' and 'cold' spots are in your tank - but theres no real accurate target here. There are way too many variables.

 

[Sleeping Giant]

I agree with your premise. Playing devil’s advocate though, it’s $60 plus a $500 deposit. Some people can’t afford to be out of pocket that much for over a week. If so, how they can afford a reef tank is another question entirely.

Cause not everyone has bags of money laying around

 

[Sleeping Giant]

You do know that BRS isn't the only place to rent a PAR meter, right? A quick search shows other places with a smaller deposit. Also, I bet a few of your LFS rent them as well.
I also suggested checking with local reef clubs. I know mine has them for members in good standing...for free!

Good luck trying to find somewhere to rent one in Canada

 

[MERKEY]

There's no such thing as "the same lights" - because PAR, phosphates, nitrates, alkalinity are all interconnected and all relevant to color and health. If you take a coral at 700 par in a tank with .25ppm phosphates/50 ppm nitrates and put it in a tank at 700 par and .02ppm phosphates/1ppm nitrates - you'll nuke the thing.

So that actual par number ends up not being that useful - you end up having to put it lower than you'd like and work it up - because too low light is always better than too high.

Its useful knowing where the 'hot' and 'cold' spots are in your tank - but theres no real accurate target here. There are way too many variables.

That was my point without getting too technical, thank u

But to do this you have to know the number at some point.

 

[BackToTheReef]

PAR is going to be a starting point for me but not the end all be all. I do want to know what my PAR levels are at various depths in the system I am planning/building. It'll be a deep tank so data is not readily available.

While I am QTing my coral my goal is to ramp up my lighting in the QT tank to the PAR level of the frags new home in the DT. Then I can adjust up/down as the coral tells me but it will be much less of a guessing game. Which is also helpful given the depth of the DT.

I really dig the spectrum reading on the seneye and might end up getting one more for that than for the PAR. However, that is more of a luxury than a necessity. I guess any tool that is going to help the likelihood of success is a good tool in the arsenal. (At the end of the day I will probably end up buying a PAR meter just to have given the size of my system and potential for a couple diplay refuges and frag tanks).

 

[schuby]

For good health, color, and growth of SPS, lighting level is just one part. There is also stability, nutrient levels (thinking of PO4 & NO3), pH, trace elements, alkalinity, salinity, water clarity (affects effective lighting level), contaminants, AEFWs, and many more.

To me, the wonder and amazement of our reef tanks is that they are so full of life! We try to control what we can, but life can't be controlled with dials, meters, and doses. Life tends towards balance. And "Life will find a way." If my reef is successful, it's because I nudge it in the right directions and don't try to exert absolute control over it.

 

[MERKEY]

I agree with all of the nutrient and other elements playing a part but If you never take par in your own tank you are ALWAYS guessing off of what others say the lights do on their tanks with other nutrients...and for a lot thats totally fine.

If you don't care then that's great but to say to people that read this thread and site to add coral in this way will absolutely result in some deaths and struggles.

You will absolutely eventually figure out what spots are hot and cold in your tank but you will never know "how" hot or cold. You will just know that this particular coral didn't like it there.

In the beginning this is all fine and dandy but When you start spending 1k+ on a single coral matching par becomes as important as nutrients.

Playing the guessing game is up to the reefer

 

[T-J]

For those of you that put corals on a reef rack at the bottom of the tank, then move it up over time....is it attached to the glass? If so, are you permanently attaching the coral to the side of your tank then? I only ask, since the PAR at your glass is probably considerably different (less) than the PAR at that same height away from the glass.

Now, of course, if you're moving the coral from the sandbed slowly straight up in the rock structure, I believe that to be a better way (without knowing PAR).