Acropora bleaching and losing polyp extension

[Reefman29]

I have had this acro for just over a month it has started to turn white on most of the branches mainly the center "stalk" and the polyps are not extending as much
Tank info
75 mixed reef
AI SOL blue lights
Water test on Friday
Ph 8.1
Alk 230 - I did a water change so it is better now
Nitrate under 2 ppm
Phosphate .07
Calcium 420
Mag 1400
All other corals are healthy including a pink stylo purchased at the same time

 

[PaleHorse]

http://www.reefcentral.com/forums/showthread.php?t=2430841

This is a good format to follow.

Whats your alk?

 

[Reefman29]

I will retest tomorrow, but normally around 4 meq/L

 

[Reefman29]

Temp is 78-79 degrees
Lighting 8 hours 2 hours blue then whites come on for 4 hours with blue and then 2 hours of blue to sunset whites at 50% max blues at 55% max
Coral was about 6 inches from water surface, lights are about 6 inches above water surface
Water changes every 2 weeks about 10 gallons or more with seachem salinity salt
Ro/DI water is from my personal unit filters are changed every 6 months
I dose Alk, ca, mag, and vodka
Equipment
Urchin pro skimmer
Quietone 4000 return pump
2 koralia power heads
Gfo reactor and activated carbon

 

[Reefvet]

First you posted this.

Alk 230 - I did a water change so it is better now

Which makes no sense at all unless you meant ppm.

Then when asked about your ALK you answered this.

I will retest tomorrow, but normally around 4 meq/L

230 ppm would be 4.6 meq/l or 12.88 dKH.

Care to clarify so we can try and help ?

 

[Reefman29]

Alk was 230 ppm but is normally around 200 ppm, I usually convert to meq/L since I use the hanna alk checker

 

[Reefvet]

Yeah the Hanna meter was a given. I have one too, they're consistent if not correct. Alk of 12.88 dKH is pretty darned high. If you moved those corals from another tank that wasn't even close to that level then you're just seeing the effects now. Alk swings are one thing that will kill an SPS pretty consistently. You see the effects of sudden RTN in 2-3 weeks.

White and no tissue is dead. If there are tips with tissue I'd frag them off and start to slowly lower your Alk.

Consistency is key to growing SPS.

Here's a funky little grow out tank I raise frags in.

Alk 7
CA 450
Mg 1400 ( high to suppress the bubble algae that's out of control right now)
35 ppt

I have Kessils over it. They turn on in the morning and run for 8 hours. No ramping. Corals are growing fast with good color.

 

[Reefvet]

Oh, I should add. The green birdsnest on the right is 8" in diameter. It was a 1" frag in February. The Orange Setosa has trippled in size in 3 months.

The reason I mention this is because you can grow corals at normal Alk. Pushing it to high 8s to 9 or so will improve growth if there's sufficient CA and MG but color will be diminished.

Were you trying to have Alk be so high ?

 

[Reefman29]

I have been keeping it constant at almost 4, I must have over dosed the past week. I thought the range was normally 3.5-4.5 meq so I went in the middle of that

 

[Reefvet]

Natural sea water is 2.5 mq/l or 125 ppm on your Hanna.

 

[Reefvet]

Highly recommended reading.

 

[Reefman29]

Thanks for the link!