Advice please! corals bleached overnight

[m3lacoste]

Hi All,

anyone experience this type of phenomenon when only certain type of corals bleached overnight? I came home and my skimmer was overflowing and my large montipora cap, digitata, setosa, cats paw type corals bleached or what appears to be bleached or stn overnight? (all coral placement upper level of the rock but even the same type of coral frags on sandbed bleached too? I have other corals (cali tort, pink lemonade, strawberry shortcake, etc. that were not affected) My parameters checked ok too. I run MH/T5 combo that I just recently changed about a month ago (Radium/Giesemann). I also added 2 seahares recently, one I found dead a week ago and the other I can't find. I've consulted some other reefers about this and they think it might be my new lights or possibly my water paraments due to a dead seahare? not sure what to think my mixed reef is about 4 years old and these corals I grew from frags were about a year old and thriving. My fish are all ok and don't look stressed.

Tank Details:
Mixed Reef
Volume: 150
Lighting: T5 4bulb Giesemann/ (2) 250 Radium (recently changed to new Giesemann brand from DD Giesemann)
Salt: TMPro
Dose: B-Ionic
Rowaphos and Carbon
Temp: 79
CA: 420
Alk: 8.0
Mag: 1350
Nitrates: 0 (salifert reading appears to be 0?
Phosphates: did not test
Ammonia: did not test

[Bogg]

Not sure what you did but water changes seem to always help

[Funkateer_1]

I doubt one dead sea hare would be enough to cause a crash like this. Same thing with lights, it would cause stress and very STN if anything, nothing overnight.

I would have an LFS check your water, especially for NH3 and NO2. Sometimes its good to get a second pair of eyes (and a second set of test kits) to check for anything off with the water chemistry.

Definitely do a 30% water change ASAP.

Was your skimmer full when it was set off? Possibly the sea bunny did release something that upset the skimmer, the skimmate returned into the tank. A flood of nasty Hydrogen Sulfide and other stuff that makes skimmate smell awful could have definitely caused a rapid coral death. The corals dying quickly would be enough to cause an ammonia spike starting a tank crash.

Just a thought. Get your water changed and tested first.

[m3lacoste]

Thanks. I should have brought a water sample last night when i was at AW buying water. I was scrambling to mix water but I mixed 30 gallons so should be ready to change tonight.

Yes, the skimmer was completely full actually flowing out the top. I dumped the cup and then it filled back up after about an hour so I had to adjust the gate valve to prevent overskimming. I did notice an unusual smell not the usual sump smell in the house but didn't think anything of it.

[cyn]

i'm sorry, dude.

also, AW actually was the one to tell me
if a sea hare dies in your tank, it can
crash your tank.

i'd call to ask them, maybe?

[pirate2876]

It's been pretty hot lately. Are you sure the temp didn't get hot?

[m3lacoste]

I run a chiller so it's not likely due to temperature unless it spiked at one point but I don't run a controller to monitor and trend this.

[keepswimming]

I run a chiller so it's not likely due to temperature unless it spiked at one point but I don't run a controller to monitor and trend this.

There is a apex for sale on here, for cheap! I would highly recommend purchasing one! They have saved people's tanks countless times from events like this happening. If it was something the controller isn't monitoring, at least you can weed out what isnt the cause.