Help with Radion XR15 pro setting

[MBX5]

Using the xr15 pro over a Nuvo Fusion 20 (L: 24” W: 15” H: 13”) 90% SPS with the RSM mount. So far I've adjusted from 40% up to 55% over the period of 1.5 months I'm now seeing some whitening (bleaching?) on 2 montis down at sand level but don't know if its too much light or too little. All my water parameters are in line and no pests so i'm leaning more towards lighting. A few days ago I made some changes to the AB+ schedule and would like some input if you think it looks okay? I know its on the long side but I wanted a more viewable light period and a moon phase.

 

[samba_dad]

How high did you mount the XR15? I have 2 above my 65g DT. Using the wide area lens with lights mounted ~12" above the water. I run them with max intensity of 80% to obtain 400 PAR about 8" underneath water line. Make sure you have the right lens on the light.

 

[MBX5]

How high did you mount the XR15? I have 2 above my 65g DT. Using the wide area lens with lights mounted ~12" above the water. I run them with max intensity of 80% to obtain 400 PAR about 8" underneath water line. Make sure you have the right lens on the light.

The RMS mounts the light 8" above the tank and i'm using the wide lens on it.

 

[mfinn]

How are the other corals reacting?
What corals?

 

[MBX5]

All the other corals look good. Polyps out and colors looking good Acros, zoas toadstool and frogspawn . It's just the 2 montis. The look good other than losing color.
Jedi was very green and purple with red polyps

Salago losing some of it's orange

Digitata and Acros still doing well

Sorry for the iPhone photos it's all I had. The polyps are usually out more but I was cleaning in the tank before.

 

[Wilsoni]

One of the more overlooked elements that contributes to Montipora coloration is Potassium. Low Potassium leads to grey/discolored montis. This may not be the case in your circumstance but it could potentially be a variable.

 

[Wilsoni]

Assuming all of your other parameters look good.

 

[MBX5]

Doing a 4 gallon change every week but maybe I'm low on potassium.

 

[Wilsoni]

That should in theory replenish it. Which salt are you using, CP?

 

[MBX5]

Standard IO

 

[Larry L]

I agree about checking potassium to make sure, but 55% might be too much light for such a shallow tank. I was asking similar questions in a thread [here] and someone commented about having trouble at more than 25% intensity with the lights 22 inches above the sandbed, which might be similar to your setup (your might be even shallower, more like 20 or 21 inches?). I was also having trouble with bleaching running 45% at 22 inches from the sandbed, have adjusted down but it's too soon to tell if that's really what the problem. (I'm also running the 80 degree lenses which increases the intensity directly below the lights.)

samba_dad commented above about running at 80%, but from how they described their setup that's with the lights probably something like 35 inches above the sandbed, which is a big difference. (The light intensity at 21 inches is going to be almost 3 times the intensity at 35 inches.)

Also, just FYI you have to be careful about comparing apples to apples when people talk about their light settings, because it depends on a combination of intensity and spectrum. I did some measurements on my XR15s with a PAR meter and found that e.g. at 50% intensity, the PAR reading with 12K settings can be 100 higher than with 20K settings (the same measurement location and intensity).

 

[Wilsoni]

Wilsoni commented above about running at 80%

That wasn't I ;) 80% on a Nuvo Fusion 20 would have your SPS looking pearly white in no time

I'm not completely sure as to the Potassium content of IO but a high Potassium salt such as CP would surely maintain your K level at somewhere near 400ppm. I use CP on my Nuvo Fusion and still dose Potassium on occasion. My K level was 415 last time I checked. My Montis look incredible. (:

 

[Larry L]

That wasn't I ;)

Oops, sorry, that was samba_dad :)

 

[Wilsoni]

Honestly I just looked at your photos. It could be that they're not getting enough light? Have you tried moving them up slowly? They look a little shaded

 

[Wilsoni]

Oops, sorry, that was samba_dad :)

No worries :D

 

[MBX5]

Honestly I just looked at your photos. It could be that they're not getting enough light? Have you tried moving them up slowly? They look a little shaded

No shading it just because of how I took the photos. The Jedi was about 1/2 way up in the middle of the tank and now it's at the same level just on a far side because I thought it was getting too much light. Maybe a par meter will be on my R2R group BRS buy this weekend.

 

[mcarroll]

You need a light meter-stop guessing at your lights intensity.;)

Get a $free [HASHTAG]#lux[/HASHTAG] [HASHTAG]#meter[/HASHTAG] for your smart phone's camera. This will allow you to get some measurements today, but while the app is loading it on your phone browse to your favorite reseller and order a handheld lux meter - about $15, delivered - much better AND safer around saltwater. ;):)

Try to measure how much area is covered by the peak measurement and how much areas covered by about 50% of the peak measurement and post results back here.