Why is my coraline turning white?

PARAMETERS (important)
Temperature: 80 degrees
PH: 7.4
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: 0 ppm
Salinity: 33 ppt
dKH/KH/Alkalinity: 12 dKH
Magnesium: 1360
Calcium: 460 ppm
Phosphate: 0 ppm
Test kits you own: API - Salifert Magnesium
Liquid or Strips: Liquid
Brand Name: API
Are they Expired?: NO


Tank size? 55g
Estimated total system? 70g

Reef, fish only or, freshwater? Reef

Current inhabitants? What and how many? 1 Yellow Tang, 1 Diamond Goby, 1 Firefish
Clean up crew? 15 Blue leg hermits, 5 Nassarius Snails, 2 Trochus Snails

How long has your tank been set-up? 2 years

Substrate.
Type? Aragonite sand
Depth? 2"

Live rock? Yes
How much? #70
Did you recently add some? No

Filtration.
Type? Live Rock
Protein skimmer? EuroReef RS80
Do you wet or dry skim? fairly dry
Maintenance schedule for filtration? Stir sand while doing water changes
Drilled tank/hang on back overflow? Drilled Tank
Sump/refugium. What's in it and how much? 30g sump
Macro? What kind? Yes Cheato

Lighting.
Lighting type? T5
Age of bulbs? 2 months

Feeding
What? Ocean Nutrition flake/ pellets, mysis, cut up shrimp, nori
How much? just enough to keep everyone alive
How often everyday?

Water change schedule.
How much? 10g
How often? weekly
What salt brand? I/O RC
Water source? RO/DI

Additives/supplements used? Kent dKH buffer, Coralife calcium, Ion Mag

Do you have a ground probe? No
What kind of flow does your tank have? Mag12 return pump thru 3 loc-line returns, 1 Koralia 3, 1 Koralia 2, 1 180gph powerhead

There are the params for my entire tank as of today. I am trying to figure out why my coraline algae is dying off. It is all turning white. Does anyone see anything that is amiss other than the low pH, and the alk being a touch high? Is it possible that one of the tests didnt come out right?

 

how stable is your Ca and Mg - does it essentially never budge or does it up and down over time?

are you talking about coralline that has been added to the tank (i.e. on a frag) or coralline that grew in your tank to begin with?

 

ibefishy

tank is 2 years old T 5 bulbs are 2 months old
was this an upgrade?

IME when lighting changes., gets brighter, coralline can die off

Steve

 

i have a solid purple back wall. it really took off when I kept my Mg stable above 1400.

 

did not notice this. I agree. Particularly if its the coralline higher in the tank/ more exposed.

How old were the bulbs when they were replaced?

If they were too old, then even an even bulb swap would be a lot more light.

 

I can only guess that it fluctuates as I manually dose on a weekly basis. The coraline that is dying off is what was there for a while since my tank was set up. I just thought of something...could it be from having to remove all the rocks twice in a two week period to catch some fish I wanted to get rid of. I put the rocks in water while they were out of the tank but would exposure to air for a few minutes be enough to kill it off?

The T5 bulbs are 2 months old as they are an upgrade from the pc's I was using.

 

having done the former myself without any noticeable loss of purple
then my money is on the upgrade from PCs to T5s being the reason
it will grow again once it adjusts to the new lighting intensity

Steve

 

i also noticed since ive replaced my bulbs , and also adding a 6500k , ive had some dieoff on my back glass too. so as said, it could very well be the reason then.

 

bingo!

 

btw - i only have to dose Mg every 2-3 months to keep it stable...