Hydra 52HD PAR Questions

[SirMilo]

Hey everyone.
I don't have access to a PAR meter which is why I am asking for your experiences with these lights.
I have seen the charts on the AI site but i'm looking more for real world experiences.

Can anyone give me any idea what kind of PAR readings I can expect with the 52HDs hanging 12" AWL at say 12" below water level. I know there are variables at play but a general idea would be immensely helpful. Knowing the settings you are using to get these numbers would also be very much appreciated.
Thank you.

 

[jsker]

different tank, different setups, will make the readings different. I would suggest to ask the LFS or the reef club in your area if the will rent of let you use a par meter.

 

[mcarroll]

The charts seem pretty realistic to me...

BTW, you don't need a PAR meter. They are nice, but expensive.

Instead, start with a free lux meter app for your smart phone. The price is right – do this now.

It uses the light meter in your camera mixed with some software interpolation - excellent for the price. There are many, both for IOS an Android. Not all apps work equally well with all cameras though, so some folks don't get good readings with the first app they pick. (search reef2reef for "lux meter app", or click one of these tags to find apps that others have used successfully: [HASHTAG]#lux[/HASHTAG] [HASHTAG]#meter[/HASHTAG])

While you're waiting for the app to install, order a $15 handheld lux meter from your favorite china reseller...search for model "lx-1010B". Much better than the apps, plus safer to use around your tank!

Converting from PAR to lux, if you had to, is pretty easy....I just use a conversion factor of 50. Just some examples....1000 PAR = 50,000 lux. Direct sunlight at the water's surface at the equator is about 100,000 lux, or 2000 PAR.

 

[SirMilo]

different tank, different setups, will make the readings different. I would suggest to ask the LFS or the reef club in your area if the will rent of let you use a par meter.

I've already attempted this only to come up empty handed unfortunately.
According to the mcarroll post, it appears that I have another option where I do have access to a tool.

Converting from PAR to lux, if you had to, is pretty easy....I just use a conversion factor of 50. Just some examples....1000 PAR = 50,000 lux. Direct sunlight at the water's surface at the equator is about 100,000 lux, or 2000 PAR.

Thanks much for this information.
I do have access to a Milwaukee lux meter locally, just not a par meter. I've had people tell me that lux isn't a reliable way to determine par but I have no clue how accurate that statement is. I suppose as long as it could get me in the ballpark, i'm not too concerned with overall accuracy.


I am running 4 of these over a 4 foot 120 and suspect I could easily cook everything from the sandbed up, thus the reason for my question. Thanks for the responses!

 

[jsker]

I bought a lux meter on amazon for $15.00 and took the top of the tank reading just now as the light are ramping up 604 par and 120,800 lux.

 

[SirMilo]

I just downloaded the Galactica lux meter to my phone and will at least get a baseline once my lights have ramped up completely at 1pm. The lack of shadowing makes them look quite bright which is causing paranoia on my part. However, some of my corals are definitely showing me that they want more light. Guess I need to make a trip to the LFS later today so I can borrow their Milwaukee.

While I am on a roll, I should probably try to get my nitrates up some before increasing intensity too much.

 

[G8trBait16]

I have 2Hydra 52 HD's over my 75g. My lights have a 2 1/2 hour ramp up and come on at 9am, go off at 9pm Peak is from 11:30am to 6:30pm. Settings are below

UV: 90
Violet: 95
Royal Blue : 100
Blue: 100
Green: 25
Red: 20
White: 25

I am bringing the whites up slowly. I have mostly SPS in my tank.

 

[SirMilo]

Thanks for the specifics G8trBait- I appreciate it.

 

[G8trBait16]

Thanks for the specifics G8trBait- I appreciate it.

Not a problem SirMilo, always like to be able to help out where I can.

 

[mcarroll]

I just downloaded the Galactica lux meter to my phone and will at least get a baseline once my lights have ramped up completely at 1pm. The lack of shadowing makes them look quite bright which is causing paranoia on my part. However, some of my corals are definitely showing me that they want more light. Guess I need to make a trip to the LFS later today so I can borrow their Milwaukee.

While I am on a roll, I should probably try to get my nitrates up some before increasing intensity too much.

As long as the tank is reasonably healthy, corals don't usually require that much light....>20,000 lux. >10,000 actually....I have two hard coral tanks – at peak, one runs around 14,000 lux and they other around 40,000 lux.

More light is definitely not necessarily better.

Unless you find out that you're lighting your tank with warm white T12 florescent tubes or something equally as crazy , I will bet that you're right to look at nutrients, flow and all other factors before adding light.

I bought a lux meter on amazon for $15.00 and took the top of the tank reading just now as the light are ramping up 604 par and 120,800 lux.

Those numbers don't match and the lux reading sounds incorrect. 600 PAR should be somewhere in the neighborhood of 30,000 lux. Sunlight in the tropics at high noon is only around 100,000 lux.

Is the PAR number a conversion or do you have a PAR meter in addition to the lux meter?

 

[jsker]

As long as the tank is reasonably healthy, corals don't usually require that much light....>20,000 lux. >10,000 actually....I have two hard coral tanks – at peak, one runs around 14,000 lux and they other around 40,000 lux.

More light is definitely not necessarily better.

Unless you find out that you're lighting your tank with warm white T12 florescent tubes or something equally as crazy , I will bet that you're right to look at nutrients, flow and all other factors before adding light.



Those numbers don't match and the lux reading sounds incorrect. 600 PAR should be somewhere in the neighborhood of 30,000 lux. Sunlight in the tropics at high noon is only around 100,000 lux.

Is the PAR number a conversion or do you have a PAR meter in addition to the lux meter?

let me run the number again

 

[mcarroll]

If you're computing, just take lux / 50 or PAR•50. That's roughly the conversion for sunlight and it's worked for all the estimating I've done so far. Plus it makes for easy math!!

 

[mcarroll]

I can borrow their Milwaukee

Forgot to mention that the main difference (to us) about the Milwaukee is that it comes with an waterproof sensor. I think they go for around $75 if you find it to be useful. Just keep in mind that what you can do with the $15 meter has been adequate for lots of folks so far. (You do have to wait for shipping, of course. )

Even if you decide later to upgrade to a Milwaukee or Apogee you haven't broken the bank @ $15 for a plain lux meter, so no worries!

 

[mcarroll]

More I forgot...

I've had people tell me that lux isn't a reliable way to determine par but I have no clue how accurate that statement is.

I can only guess they hadn't even tried (most people) or that they were doing something different than we are. Check out some of Dana Riddle's articles...he is where I got the idea to use a lux meter.

I suppose as long as it could get me in the ballpark, i'm not too concerned with overall accuracy.

Bingo! This is also how your corals look at it, so you're in good company!

I think of my water test kits like this. They really blow for accuracy. ICP-type analysis blows them away – by a lot.

For some reason, my reefing has not been impeded by this lack of ICP testing. My lux meter has not gotten in my way either!

In fact, both generate data that is perfectly usable for our purpose.