help 2 year old table sps rtn

[8mycash]

I have a 2 year old sps table colony. out of the blue it starts to RTN. It has been healthy and no problems for 2 years, suddenly starts to bleach out. I have broken the colony up trying to stop it, but the bleaching is still happening. Any ideas? water quality is perfect. All bulbs are new.

 

[Greg Hiller]

>water quality is perfect.<

Define perfect please.

 

[Wiskey]

And flow. Often as corals grow they block themselfs from flow and start to die because of it.

Not too bright are they?
Whiskey

 

[fishypets]

Inspect for pest like the dreaded AEFW. You will never see then unless you dip your corals and squirt with a turkey baster

 

[8mycash]

<a href=showthread.php?s=&postid=8305234#post8305234 target=_blank>Originally posted</a> by Greg Hiller
>water quality is perfect.<

Define perfect please.

All water tests show everything is in correct levels. ph, alk,nitrate, nitrites ect.. I have just changed my bulbs from 20k to 14k. I changed the water flow 2 weeks ago. could that do it?

 

[JamesJR]

<a href=showthread.php?s=&postid=8305830#post8305830 target=_blank>Originally posted</a> by 8mycash
I have just changed my bulbs from 20k to 14k. I changed the water flow 2 weeks ago. could that do it?

Hmmm. I am by no means an expert on all things metal halide but I do remember reading somewhere that there was a huge difference in the intensity or PAR readings in a 20k bulb and a 14K bulb. I think it said that the higher Kelvin reading lamps have a lower PAR reading so dropping to a 14K may have been a huge shift in lighting intensity for the coral. Did you raise the lights for a while or put a screen on when you switched? any other corals giving you problems?

 

[8mycash]

one other coral started showing problems this morning. I just switched out the bulbs and adjusted the flow a bit. Maybe a combo problem. If they shed their color are the dead or will it grow back.

 

[VikeBron]

What brand of bulb did you switch from and to?

 

[8mycash]

went from hamilton 20k to hamilton 14k

 

[JamesJR]

<a href=showthread.php?s=&postid=8305830#post8305830 target=_blank>Originally posted</a> by 8mycash
I have just changed my bulbs from 20k to 14k. I changed the water flow 2 weeks ago. could that do it?

Hmmm. I am by no means an expert on all things metal halide but I do remember reading somewhere that there was a huge difference in the intensity or PAR readings in a 20k bulb and a 14K bulb. I think it said that the higher Kelvin reading lamps have a lower PAR reading so dropping to a 14K may have been a huge shift in lighting intensity for the coral. Did you raise the lights for a while or put a screen on when you switched? any other corals giving you problems?

 

[theatrus]

Hamilton 14k are very bright on HQI and EBallasts. Could have been light shock, but usually doesn't lead to RTN.

 

[rigleautomotive]

what is your alk.real high alk over 11 will do that sometimes,combined with light shock.

 

[Frankysreef]

I changed my flow and a 2 yr old mille colony rtn'd overnight...

Frag it and give it lots of flow. Tables like flow all around the coral including the bottom... Ledges are very good for these guys.

 

[LobsterOfJustice]

I'm betting a change in water flow. Tables are very picky about flow. They need plenty of it to keep things from settleing on them, and enough flow around the base. If it grew to its current shape in one condition and then you changed the flow, that could start RTN.

 

[8mycash]

dang it, wish I would have thought about water flow. Just a learning lesson I guess.