Sps Stn?

[Syris]

I am having a problem for the past couple months with all my frags/small colonies. First the growth seems very slow and secondly all of them eventually get a white bleached spot or 2. This does not take over the frag and kill it, area just turns white slowly and that area eventually dies but the rest of the frag will live on.
Specs,
Reef is 1yr old
Temp 78-79
Sal 1.024
Ca 410
Alk 10.6 dKH
Mg 1320

I do Bi-weekly 15% water changes. MH are on for 9hrs/day Actinics 12hrs/day
2x Modded MJ 1200s for flow
Small/medium Bioload
run carbon 24/7

Could high NO3 or PO4 be the cause? My test kit shows zero for these but I dont know if I believe it.

 

[Greg Hiller]

Syris,

Haven't seen you around much lately. Sorry to hear you are having problems. If you tests kits are right, I certainly don't see any problems there. How old are your bulbs? What type of bulbs are you using? Did you have good growth before?

 

[Reef55]

PO4 was definitly the problem in my tank. I would not recommend a course of action though unless you measure a parameter that is out of line. Carbon / waterchanges can never hurt though.

 

[Syris]

Hi Greg hows it going?
Yeah Ive been off the boards lately due to increased work load at work.

The MH bulbs are only ~5months old but they are the Coralvue Reeflux bulbs. Last time I tried Coralvue bulbs a couple years ago I had a major bleaching event 3 months into em. But these are suppose to be the new improved bulbs. I may go back to XM 10ks, never had these issues with them. I dont want to jump the gun and blame the bulbs just yet, but it is suspiciously similar to the problems I had before with Coralvue.

Reef55,
Did you have slow growth or tissue issues when you had PO4 problems? I have a Phosban filter I may refill and put back online and see what happens over a course of a month.