corals bleaching???? help.

[softbal4]

so my tank has been doing awesome. saturday i started to get a little worried with the heat. with 2 400watters on my tank was in the 83 - 84.5 degree range and i usually run 1 400watt 10k and 2 400 watt 20 k's for about 7-9 hours. so i turned on the central air and everthing cooled down. my tank now has been running 80- 82 with all 3 lights on. i noticed that my slimer was bleached and that i had a couple of spots on my 12 inch monti colony. what is up? i don't want to loose anything more. i did a chemical test. ph is 80.7 ammonia 0 nitrate 0 nitrite maybe a slight 0.1... for the last couple of days some zoos colonies have not fully extended...but most are and everthing else seem ok.

What should i do other then a water change. the tank is 220gallons....i am in the process of making extra water.

sorry for rambling. thanks for all assistance.

[menard]

A fluctuation of + or - 5 you will see sign of stress on some corals if you let this go for more than 3 days ( say good bye to your investment ) A big tank like U have why not buy a chiller keep that temp. steady. 3 yrs . ago I lost all my deep water Acros. we as a family went out for dinner and soon I open up my door I smell something i knew then its the tank. The tank temp hit 89, intantly killed my acros. :( Now I have one and another extra just in case.......PEACE

[Sk8r]

Your rock and sand take days to cool down, that's your problem. Keep the ac on during the day and you should be ok. THe water change should help. Corals can recover if not too far gone. Just keep temp stable and water params immaculate. That ph is a bit low. Check alkalinity.

[Rod Buehler]

Bleaching or loosing tissue?

IMO a few degree swing (80-84) is not going to cause any problems.
I would also check Alk , calcium, and phosphates

[Racenrich]

ive noticed that if a little salt creep falls into the tank and lands on a coral...wala...bleached spot or spots.....its happened to me.....Just an FYI!

[softbal4]

menard, you are right about the chiller. i told myself a chiller was a smart idea and i let others tell me that if i run the air i would be fine. stupid move.

i thought my ph should be between 8 - 8.5....am i wrong on that?

i just don't know what is going on....now there are 4 zoo colonies that are not completely opened...
a water change is next on my list but making a crazy amount of water is taking some time. are there any other thoughts as to what could be up and what i should do? what kind of water change should i do? 20% ?

thanks for the help....this stuff really makes the hobby trying!

[aurorafish]

kalk will raise you ph , do it like .1 increase daily not all at once, is the 8.07 with lights on or off?

[marilynrn711]

I cannot believe your temp swing to 84 would cause those problems. Mine has reached that a numerous times in the summer, without problems.

[marilynrn711]

Another thing to consider is whether that is an accurate temp. How are you measuring?

[softbal4]

ok just did a 40 gallon water change and checked the alk and ca levels.

alk is 4.57 meq/l
calcium is 430ppm
temp is 83.3
ph is 8.4

marilynrn...i have a little coral life thermometer in the sump and a lifeguard in the tank.

aurora that was with light off. now ph is 804 having the lights just go off.

so obviously my alk is tooo high. would this have caused the problem....everything else has checked out ok. i am hoping i can save my monti still.

any suggestions?