Radion XR15 Questions??

Brandon Rush · Mar 28, 2019

So I've had a Radion G4 XR15 with a diffuser for some time and had a couple questions I'm hoping some people can chime in on. I just recently bought a PAR meter and learned that my lights are only producing about 90-100 PAR close to the surface of the water with the lights at about 55% intensity. I've tried to grow SPS in the tank in the past and it always looked good for a few weeks then bleached out. Wondering if the lack of light would have caused it? I'm currently running a Reefer 170 with the Ecotech RMS arm. All my other corals look great, but SPS would always die. I've read that the ideal PAR is around 200-250 for SPS. Would a good plan be to slowly start raising the the light intensity to acclimate all the other corals to get it to that ideal PAR range? Any and all help welcome

saltyfilmfolks · Mar 28, 2019

Yep. Simple as that. Slowly keep raising the peak par.

Daniel Waters · Mar 28, 2019

Brandon Rush said:
So I've had a Radion G4 XR15 with a diffuser for some time and had a couple questions I'm hoping some people can chime in on. I just recently bought a PAR meter and learned that my lights are only producing about 90-100 PAR close to the surface of the water with the lights at about 55% intensity. I've tried to grow SPS in the tank in the past and it always looked good for a few weeks then bleached out. Wondering if the lack of light would have caused it? I'm currently running a Reefer 170 with the Ecotech RMS arm. All my other corals look great, but SPS would always die. I've read that the ideal PAR is around 200-250 for SPS. Would a good plan be to slowly start raising the the light intensity to acclimate all the other corals to get it to that ideal PAR range? Any and all help welcome

I think shooting for a 200 par level is a good goal for long term health of acros and other SPS. However, since you said you have corals bleaching, then this leads me to believe you have other issues going on in your tank that need to be addressed before you start acclimating your corals to higher light intensities. Your corals can bleach for reasons besides too much light....any type of stress may cause this. Alkalinity swings, temperature swings, flow issues, water parameters, pests, contaminants, etc... I'd try to figure out why your other corals bleached first.

Brandon Rush · Mar 28, 2019

saltyfilmfolks said:
Yep. Simple as that. Slowly keep raising the peak par.

Thanks for the input

Brandon Rush · Mar 28, 2019

Daniel Waters said:
I think shooting for a 200 par level is a good goal for long term health of acros and other SPS. However, since you said you have corals bleaching, then this leads me to believe you have other issues going on in your tank that need to be addressed before you start acclimating your corals to higher light intensities. Your corals can bleach for reasons besides too much light....any type of stress may cause this. Alkalinity swings, temperature swings, flow issues, water parameters, pests, contaminants, etc... I'd try to figure out why your other corals bleached first.

I truly believe the case was the lighting as all other corals on my system are doing fine and I have a pretty long established tank

Daniel Waters · Mar 28, 2019

Brandon Rush said:
I truly believe the case was the lighting as all other corals on my system are doing fine and I have a pretty long established tank

A coral bleaching from too little light? I guess it could happen, but is not typical in my experience. I've seen some acros fade / slowly die from too little light but that is something that typically takes weeks. Maybe this is what you are describing when you are say bleaching? SPS can be tricky. I swear I think I've had some die just because I looked at them the wrong way and they wanted to spite me!

maroun.c · Mar 29, 2019

believe theyd be more likely to brown out and loose colors under lower light but don't think theyll RTN STN because of it

Brandon Rush · Mar 30, 2019

Daniel Waters said:
A coral bleaching from too little light? I guess it could happen, but is not typical in my experience. I've seen some acros fade / slowly die from too little light but that is something that typically takes weeks. Maybe this is what you are describing when you are say bleaching? SPS can be tricky. I swear I think I've had some die just because I looked at them the wrong way and they wanted to spite me!

I guess I may have my terms mixed up. The best way to describe it is they do well for about a month then slowly begin expelling their algae

Brandon Rush · Mar 30, 2019

maroun.c said:
believe theyd be more likely to brown out and loose colors under lower light but don't think theyll RTN STN because of it

I think this is what is happening
They do fine for a month then slowly start loosing their color

Daniel Waters · Mar 30, 2019

Yes, @Brandon Rush , I believe what you are describing is a slow starvation process occurring. I would agree with your plan to acclimate your corals to higher intensity levels.

Typically, coral bleaching is where corals expel their zooxanthellae, and it is usually something that may happen very rapidly (i.e. you wake up the next morning and the coral has completely bleached). Rapid Tissue Necrosis (RTN) can also occur that may look like a bleaching event but really is a different issue. In the case of the tissue being lost slowly over days or longer, many people refer to this as slow tissue necrosis (STN).

I think you have probably diagnosed your issue correctly. That's half the battle or more in my opinion. When I first started with sps, it took me 6 months before I realized I didn't have enough light (thank you par meters!). Now I still have issues with rtn and stn from time to time and that can really be a challenge to figure out!