Help with a PAR meter. Please

[Amy Dawson]

I got a PAR meter online to measure my lighting. I accidentally bought the kind of meter that doesn't have the attachment to go underwater. Is there anyway I can still use it without putting the meter in the water?

 

[saltyfilmfolks]

I got a PAR meter online to measure my lighting. I accidentally bought the kind of meter that doesn't have the attachment to go underwater. Is there anyway I can still use it without putting the meter in the water?

What model did you get?

 

[Amy Dawson]

This is the one I got

 

[saltyfilmfolks]

Oh. That's a lux meter. That's fine too.
I'm one of those lux meter guys. I actually own that meter and reccomended it a lot.

Firstly you could return it. It's Amazon. Love them. Kinda.

Unless I had a deep tank or was just curious. I wouldn't worry about what you have at the bottom.
You might Be able to test it dry if you hold the light over the meter the Same distance as your sand bed. Easier said than done.

But you can and I do just test at the surface of the water.
Then devide that number by 40 50 and 60.

That is you par range. For most lights

40 for t5 and MH
50 is the sun
and 60 is a decent LED.
That's the range best to ok for any light you have. And both of ours fall into that range.

Pers I think it's ok to guesstimate the bottom. If you have par for acros on top you just probably don't have mushrooms on the bottom 19 inches away.
Unless they are shriveld and mad like mine are.

Hope this helps.

 

[Amy Dawson]

It does and I'll give it a try. Thank you ver much

 

[saltyfilmfolks]

It does and I'll give it a try. Thank you ver much

Tag me if you need anything!

 

[edinphilly]

Could you put it in a ziplock bag and use it underwater? I seriously don't know so I'd be interested if anyone knows.

 

[saltyfilmfolks]

Could you put it in a ziplock bag and use it underwater? I seriously don't know so I'd be interested if anyone knows.

Yes you could.
I hope it is a good bag.

I had to put my spendy meter in a swimming pool on a movie I did once in a bag.
Not a happy day. It did work and come out dry though.

 

[Amy Dawson]

I put it in a bag and it worked great. Thank you! So my PAR on the sand bed is 450. Is that about right?

 

[saltyfilmfolks]

Double check what you see on the screen. Is it 4500?

The meter reads in lux so it is intensity only.

If that's correct you devide by 50 as an average. (See above post)
That would be approx 90 par.

What is the reading at the top of the tank right at the water level?

I put it in a bag and it worked great. Thank you! So my PAR on the sand bed is 450. Is that about right?

 

[Amy Dawson]

So it's 1100 on the top of the water

 

[Amy Dawson]

If 60 par is good for an led light. Is it 60 par at the water surface or 60 par on the sand bed

 

[Amy Dawson]

Omg I got it lol. I'm sorry

 

[Amy Dawson]

Just one more question. I have two switches on my led's one is for the blue lights and one is for white led lights but they also have blue, red etc in them. I have been using only the white lights and leaving the blue off. I read somewhere that the blue lights are not needed. Just want to make sure this is right.

 

[ReeferBob]

Again, a PAR meter is totally different than a Lux meter.

 

[saltyfilmfolks]

Just one more question. I have two switches on my led's one is for the blue lights and one is for white led lights but they also have blue, red etc in them. I have been using only the white lights and leaving the blue off. I read somewhere that the blue lights are not needed. Just want to make sure this is right.

One theory, Depending on the coral they like more blue as they are deeper water animals. Another theory the all like a lot of blue as it stimulates photosysnthseis across the board.
The white lights depending on the brand are very likely 10,000 degrees kelvin color temp. Many prefer to run in the p14,000 to 20,000 degree range.
Many also will start with the blues to get the photosynth benefits and make the corals pop. Then turn on the whites with the blues to achieve the desired color temp for growth and appearance. And then the whites go off in the evening to get the blue pop.

My preferred method is to turn the whites and blues on together and adjust the color to eye judging purely on appearance.
Then Meter both together and adjust both evenly keeping the same white blue ratio to the desired peak intensity.
For an 18 to 24 in deep tank with lower light animals I would target 20,000 to 25,000 lux measured at the top of the water.
If your corals are fine don't worry about it just find the number for future reference.

Again, a PAR meter is totally different than a Lux meter.

Correct.

 

[saltyfilmfolks]

Omg I got it lol. I'm sorry

You got it? Sound like it.

I'd prefer to speak in terms of lux.
Because of the wide par estimate depending on your fixture it probably easier than doing the rough conversion.

What fixture are you using BTW.

 

[saltyfilmfolks]

If 60 par is good for an led light. Is it 60 par at the water surface or 60 par on the sand bed

This depends on the animals your going to keep in the tank. 25 to 50 par probably isn't enough for a nem. But probably fine for mushrooms.

This is something most all of us learn from trial and error and reasearch.

It doesn't help that they only give light requirements in high med and low.
Is medium 1000 par or 150.
I belive it's 150.

 

[Amy Dawson]

Well I was def frying my corals before. I'm so glad you told me to get the meter. I already notice a difference in them. I'm using Mars aqua led fixture. I was thinking about switching to MH but I'm not sure. I just got the leds so I think I'm going to give them a few months

 

[Amy Dawson]

Thank you so so much for your help!