Corals anemone declining!!

help!

i realise my corals aren't so happy anymore after i introduced the chiller 2 days ago.. one of the branches of my torch coral is dead, and the other one not so good.. my bubble tip shriveled and closed up for a while too , first time seeing it happen.

the night before i introduced the chiller, i put a fan on it, the temp dropped from 28.5 to 26.3c the following morning, then i got the chiller and set it to 25.5.The chiller only chills when there is 2 degree celsius diff, so the temp fluctuates between 25.5 and 27.5 ( takes around 2 hours for temp to rise 2 c) is the temp fluctuation that killed my torch?

water parameters
ammonia nitrite -0
nitrate 10ppm
sg 1.024 ph 8.3
alkalinity - 8dkh
calcium 560
magnesium 1140

Could the other reason be high phosphates? i recently had a red slime algae bloom.. seems to be worsening this 2 days. i've read that it harms corals .
Should i perform a 40 percent water change tomorrow ? ( just prepared the saltwater ), sigh i'm at a loss here.. :-/

 

I think your temperature range is too wide, that's about 78F to 81.5F. I would try and keep it within a degree or two Farenheit (.5 to 1 degree Celsius) if possible, a big swing can stress/kill them.

Phosphates could have added to the problem, I don't know if I would do a 40% change, maybe 20% once or twice a week for a few weeks IMO.

Also I would bump your salinity to 1.025 personally (and use a calibrated refactometer), also your magnesium is a bit low for that calcium level. You should have about 3x your calcium level in magnesium.

 

i know but the chiller's set that way.. i will try to use an external thermostat to set it to start chilling when there's a 1 degree difference.. do you suggest i do a water change now to remove some of the phosphates?

 

I really dont think the temperature is the issue. Mine goes up to 80 or 81 some days and is usually about 78. I think thats common.

 

yeah but the thing is, my room temp is 30 c, so my chiller will chill my tank to 25.5 c, it will rise to 27.5 c in 1 hour plus to 2 hours, then it will chill to 25.5c again. this cycle repeats itself all day. causing constant fluctuation. is that fine too :-X

 

another item to keep in mind is the age of your lighting.

Just in my experiance when the tank is doing great almost on auto pilot for around six months then starts to sour out and by the tenth month stuff really starts going bad with corals shrinking and looking sick I remember that my lighting is at a year old and start to save the tank again. Happens every year to me. lol.