SPS corals turning white

[Ladams]

I am new to the forum and recently two of my SPS corals are losing color and turning white. Any advise. All others seem to be doing well

[crumbletop]

How old are your bulbs? A friend of mine had a bunch of sps turn white when his bulbs started getting close to the year mark (XM 14Ks, I think -- maybe 10Ks). They are coloring back up since he replaced the bulbs.

[Ladams]

I am using 2 250 Watt 14000K HQI bulbs that are about 1 year old. The 2 90 watt actinics have been replaced about 2 months ago. I will try to replace the HQI bulbs. Thanks for the advise

[jdieck]

Check your water conditions and parameters just in case but if it is limited to two corals look for parasites.
Use a good magnifying lenss to look for transparent acropora flat worms, look also for red bugs and if they are montis look for nudis.

[Buster4900]

I think I have heard of this happening when temperature swings alot??