Am I doing it wrong? PAR readings?

[jason the filter freak]

I think I'm doing it wrong?

Using an Apogee MQ510 in perfect condition as far as I know.

 

Also is there a template or program out there to grid your tank in 3D to record readings on?

 

I'm testing my lights Radion XR30pro G4 WITH Radion diffusers on RMS mounts (about 7" above tank+ 2.5" rim to waterline) and about a 10-15 degree tilt toward the back of the tank due to the weight of the XR30 or "design" of the RMS

 

I've attached a diagram of the lighting and tank. Sand bed is black and about 2" deep. 

Tank is 24" x 32" x 24" LxWxD. Lights are about 3" from each left and right edges and about 4.5" back from front edge. 

 

Also attached is the lighting scheme. I was running the preloaded radiant color scheme at 59%.

Anyway took some measurements figured I was doing it wrong and gave up. Dead center in my tank left to right, top to bottom, front to back I got ~315 PAR (took the measurements at 57% not full 59%) and all the way down on the sand bed approx 1" from the glass and approx 7" I was getting ~330 PAR.

 

Also of note I'm just remembering I had forgotten to shut off my pumps. So I'm guessing the par may be higher and I can't recall if I scraped the glass first.

 

I realize 2 x XR30PRO are big for this tank but I was truely caught off guard by the readings. 

 

Is it possible I'm getting it right before I go though and do a ton of readings? (With the pump off) And adjust my lights to desired PAR 70-150 or so. 

 

TIA

[khh27]

Could it be because the 2 lights are intersecting further down results in the higher PAR at the bottom vs in the center?

Sent from my SM-G960U using Tapatalk

[khh27]

But your pumps could also be throwing it off

Sent from my SM-G960U using Tapatalk

[YHSublime]

Are the numbers higher than you thought? You're probably def throwing the readings with the pumps still on. 

 

For reference, my lights (custom built, but designed to mimic x3 gen 3 radions, hung 12" off from my water line, at my peak par space gave me about 315-320 at 75% after about 4-5 years of use. 

 

The numbers are kinda of arbitrary though, are your corals happy, colored up, and growing? 

[jason the filter freak]

4 hours ago, YHSublime said:

Are the numbers higher than you thought? You're probably def throwing the readings with the pumps still on. 

 

For reference, my lights (custom built, but designed to mimic x3 gen 3 radions, hung 12" off from my water line, at my peak par space gave me about 315-320 at 75% after about 4-5 years of use. 

 

The numbers are kinda of arbitrary though, are your corals happy, colored up, and growing? 

 

No they're not particularly happy at least some of them it's a zoa/paly only tank so ideal PAR is more like 50-200 average depending on who you believe. 

 

I've been having "unexplained" shrinking and melting, that I now assume may be linked to baking my polyps. 

 

I'm cutting my light intensity way back. Extending photo period a bit longer, closer to 10, than the 8 I was running and hoping for improvement. 

 

I did have an incident or two recently with my tank becoming "too clean". I.e. nitrates undetected by chemical and photo tests and phosphates being sub optimal as well. So I thought that was my issue. 

 

[jason the filter freak]

4 hours ago, khh27 said:

But your pumps could also be throwing it off

Sent from my SM-G960U using Tapatalk
 

 

I would have assumed pumps on would have lead to artificially low numbers. But I am planning on rechecking today. Both my old lighting scheme and my new one. 

[YHSublime]

I’d dramatically cut the lighting back. By a lot. You’ll know if you need more, adjust up slowly. 
 

as for water being to clean, I moved subie zoa cuttings into a new tank from my DT, one without a skimmer, cheap light, and I don’t do water changes often, and every cut or frag is doing x10 better than my clean mixed reef DT. Polyps are larger, things are growing faster, it’s like the less I care, the better they do…