If you have not run a PAR meter on your tank do it now

[chemaholic]

I bought a PAR meter from BRS and started playing with it tonight and wow. My lighting across the board is way too low. By a lot.

Now I truly realize my eyes don't mean jack when it comes to PAR. Places that look bright are actually 50 PAR or lower and I am not talking on the sandbed here. I am talking halfway up my tank is 50 PAR. I made a few changes but nothing drastic. I need to spend some time really taking measurements, adjusting lighting, and thinking about coral placement.

My frag tank really set off alarm bells. I need to raise my lights way up and center them. I also need to measure and place coral appropriately. Centered on the light and sitting on the frag rack the PAR was a bit over 100. a few inches off center was 50 and the edges were 0. No PAR. Spillage be darned I need to raise these lights a good deal maybe get a diffuser so I can balance out the PAR better.

Speaking of I need to go find some diffusers for my XR15's on my frag tank and maybe find a third XR15 to make coverage more even.

 

[dball711]

I wouldn’t be rushing to use diffusers, most likely they will decrease PAR a bit in the center and raise it a bit away from the center but not much. what are you running your XR15’s at, how far away from the water surface, how deep is the tank? Saying half way up a tank means nothing with out a number.

 

[billyocean]

Par isn't everything either although yours is indeed mighty low. Radions don't put out really high "par numbers" either but the quality of the par is excellent. Basically, what I get out of 400 par you might get out of 3/350 on radions depending on spectrum/schedule.

 

[chemaholic]

The DT is 25" deep. It is running 32HDs. The frag tank is running G4 XR15s 10" above the water with frags sitting about 4-6" below the water.

Right now the tanks get 12 hours of total light with 1 hour ramp up and down so 10 hours of full light. I am running AB+ on them.

 

[dball711]

Do you know what intensity the lights are set to run at? What percent are the set to ramp to?

 

[chemaholic]

Right now they are running at 25% intensity.

 

[dball711]

Is that the level they were at when you took PAR readings, if so then the intensity is too low.

 

[chemaholic]

One was a little lower than the other but yes. I will experiment with it when I get home. I have mostly zoas in the tank, but I have a variety of other coral types in there as well. I will adjust the intensity, take measurements, and place corals based on their needs and the measurements I get. That should help. I really appreciate the feedback on this. I am also getting a used reefkeeper V2 to try out. I am curious how the spread is and what PAR readings I get with it compared to the XR15's.

 

[phi79]

I run my g5 at 90% for 6 hours

 

[chemaholic]

I run my g5 at 90% for 6 hours

What kind of tank and what kind of coral?

 

[phi79]

It’s a 180g water box mixed reef. I have 6 xr15 and t5

 

[chemaholic]

Yeah mine are too low lol. I lost some cyphastrea a few weeks back and I assumed the lights were too high since they like low light. Maybe it was the opposite. All I know is without the PAR meter I would have had no clue where my lights were and I would still be running them too low.

 

[phi79]

Slowly crank it up and let us know what are the PAR

 

[billyocean]

Tip: kill your flow to get the best idea when taking readings

...in case you didn't know already

 

[chemaholic]

I did not. I was thinking about trying to take reading with the water moving like it would normally. I will do it with the water stopped though.

 

[reefkeeper]

Tip: kill your flow to get the best idea when taking readings

...in case you didn't know already

That's a great suggestion. I have a PAR Meter and take readings often and BillyOcean is correct. The water flow will give you different readings when the pumps are on and off.

 

[phi79]

But you normally run your tank with all the flow on and I think that is a true measurement.

 

[skrappy]

But you normally run your tank with all the flow on and I think that is a true measurement.

Hard to get useable measurements when it bounces 75 PAR up and down with each wave. The goal of the PAR meter should be to get a consistent baseline to assist with mounting height and intensity, it is not possible to get consistency when the waves can never be consistent, best you could hope to do is average the numbers in your head while you watch them bounce all over the place. I strongly recommend to turn off all flow while taking PAR measurements, and use them as a guide not as a precise number.

@chemaholic also make sure you have the correct mode selected, you want to use the "Electric" mode for our hobby, not the "Sun" mode.

 

[billyocean]

But you normally run your tank with all the flow on and I think that is a true measurement.

It is. But you want to know what the constant is. At least in my case..the flow is random so I could test one hour and test the next and it's bouncing around the whole time either way. It's smart to test with no flow and then test with flow but it bounces around a bunch if you have surface agitation as you should.

 

[chemaholic]

Slowly crank it up and let us know what are the PAR

I ordered the stick thingy for the sensor. Once I have that I will be taking measurements on my tanks. I will post the results.