Corals look dead overnight, 3 fish died???

Brandon103095 · Apr 2, 2020

Hi all, yesterday everything in my tank looked great, thismorning i found 3 dead fish, and multiple corals look bleached. I immediately removed the fish and didnt see any signs of disease or damage. There are still 4 fish and one shrimp that are acting completely normal and a few of my corals still look OK (leather, rock flowers, gsp). I attached pictures of my test kit and corals that look dead, please help! The only thing i added into my tank recently is a few rock flower nems, do you think that caused this?

vetteguy53081 · Apr 2, 2020

Im going to point to salinity and temp
What is your salinity and tank temp?
Also PH ?

When you stick finger of water, do you get a jolt of stray voltage ?

Brandon103095 · Apr 2, 2020

vetteguy53081 said:
Im going to point to salinity and temp
What is your salinity and tank temp?
Also PH ?

When you stick finger of water, do you get a jolt of stray voltage ?

salinity 1.025 temp 78. didnt notice any stray voltage
PH looks between 7.5 and 8 from test kit

Ewok1 · Apr 2, 2020

Brandon103095 said:
salinity 1.025 temp 78. didnt notice any stray voltage
PH looks between 7.5 and 8 from test kit

It could be poison do you have nudibranchs or sea cucumbers? Maybe copper?

HAMMERofGold · Apr 2, 2020

I see some Palys in one of your pictures, maybe they released Palytoxin? I'd also check Phosphates and Magnesium levels. They could've been rising/depleting gradually over time and just recently hit a threshold where certain species cant survive.

lpsouth1978 · Apr 2, 2020

Unfortunately it could be any number of things causing this. Both fish and corals perishing over night is not very common. Usually the fish can survive conditions that would kill corals and visa versa. First thing I would consider is contaminants or poisons. I would get some carbon in there in case that is the issue. Also make sure you have good surface agitation and gas exchange.

Finally, and VERY important, get some real test kits. The strips may very well be the worst testing equipment available and, IMO, should not even be sold.

Billdogg · Apr 2, 2020

Hope I can help!

Although the test strips appear to be in the ok range, they are not the best choice for water testing anytime past the initial cycle. I don't see a result for Ammonia? There is a good chance that when the first fish died there was an ammonia spike that then pushed the other two over the edge. Corals are very sensitive to changes in water chemistry .

RedSea makes a pretty good kit. I prefer Salifert because I can get consistent, repeatable results. They are also reasonably priced.

I would consider an upgrade in the testing department.

More details about your system would also be helpful. How big and how old is it? What lighting are you using? How much flow? Skimmer? Carbon?

I notice that you have a mix of soft and hard corals. Google "Allelopathy" Soft corals release turpines in the war against the stony corals. That, too, could be a part of the problem. Carbon and a good skimmer will alleviate that problem easily.

Keep us updated!