RTN in 24 hours?

[Blue Carbon Reefing]

I in the last 24 hours have experienced an issue with my corals. All of my corals do not look happy. They are not opening up and some of the SPS corals a blue Tort and a Green Slimer have RTN in what seems to be 24 hours or less. Even my montiporas are turning white but I still see some polyps on them. The only thing that has changed is I changed a couple of lines of code on my APEX and my two protein skimmers were both shut off for the last 24 hours and I also had all 4 of my MP40s off for the same time period so the only water movement in the tank is from the main return pump which goes from the basement sump up to the main level at an estimated 3000 GPH for a 400 Gallon Main display. I have an 1100 gallon total system all plumbed together including a frag tank and the ORP levels seem to be unchanged with these two things shut down. Orp at 450 to 467. I can only think of having both of these things shut down for around 24 hours is the culprit. I did not test any other parameters other than salinity because my salinity probe was registering a drop. my salinity is down to 1.023 but the plan there is to add fresh salt water to my top off bring that back up. I normally run at 1.025. Do you think that 24 hours with those two things shut down is the culprit or should I be looking deeper into this? I am just surprised that literally overnight 2 year old Plus Acros just turned white and everything else including soft corals looks unhappy and closed up.

Thank you!

 

[nautical_nathaniel]

I would check your other water parameters. I suspect turning off both of your protein skimmers for such a large system has had some sort of impact overall.

 

[five.five-six]

1.023 shouldn’t hurt anything unles it is acutely sudden. I had been running my SPS dominated tank at 1.023 untill christmas when I got a new digital refractomter and found the problem.

This seems awfully sudden for just losing the gas exchange of your skimmers. I might look for other issues. Run a full set of tests.

Happy reefing and may the odds be ever in your favor.

 

[reefwiser]

Across can do this they are so so sensitive to any change the water movement down for 24 hours can totally change the conditions in the tank

 

[Blue Carbon Reefing]

Thank you all. I have a feeling this is the culprit but I will do further testing to make sure nothing else is out of line.

 

[nashorn]

Hmm ..... still could be anything.
But lack of oxygen level in the tank may have killed off stuff in the live rock.
How's ever thing else in the tank? Fish invert?
I uses to do massive water changes but notice sometime it causes more harm.
I was down to 1.20 before noticing anything with my sps.
Check skimmer pumps , stray voltage leaking voltage, alk dump, kalk dump, the list goes on and on.
Good luck

 

[Blue Carbon Reefing]

Hmm ..... still could be anything.
But lack of oxygen level in the tank may have killed off stuff in the live rock.
How's ever thing else in the tank? Fish invert?
I uses to do massive water changes but notice sometime it causes more harm.
I was down to 1.20 before noticing anything with my sps.
Check skimmer pumps , stray voltage leaking voltage, alk dump, kalk dump, the list goes on and on.
Good luck

I have had stray voltage in the tank before but have a grounding probe in the tank after shocking myself a couple of times. I have been removing my fish from the main system with an Ich outbreak to go fallow and am down to the last 4 fish. I did notice my last firefish was missing yesterday but the other fish in the system were breathing normal and I did not notice any inverts acting any different. It is common for the firefish to hide sometimes and not come out so I was hoping he was just hiding yesterday. I could not find any sign of him under any rocks or outside the tank. I have lost firefish before in QT due to lack of oxygen when medicating prazipro. I am assuming they are more sensitive to a reduction in oxygen as they are not real active swimmers. That was another sign to me that lack of oxygen might be an issue with the lack of skimmers running and the MP40s turned off. That is also why I turned the MP40s off completely because the food stays in the fish trap better without the extra flow. I will be home in a few hours to test all of the major parameters I can test for.

 

[Blue Carbon Reefing]

Ok all, update being at home today. Firefish was out and about today swimming around so he is definitely still kicking. That is good news number one. Number two is nothing looks like it is in worse condition and everything is a lot more lively today with polyp extension again so it is only the few acros that are probably gone in that short period of time. I did test most of my parameters today so here is what it looks like.

Salinity 1.023
Ammonia 0 PPM (API)
Nitrite 0 PPM (API)
Nitrates 0-2 PPM (API) I am guessing it is near zero. Color is pretty much zero, no where near the color of 5 PPM
Alk 7.3 and 7.2 Tested twice (Hanna Checker) (Normally 8.5)
Phosphate .04 PPM (12 PPB Phosphorus on the Hanna ULR Phosphorus checker)
Calcium 383 (Hanna Checker) (Normally 400 - 410)

It appears Alk and Calcium are low but I am curious what those numbers would be if my salinity was 1.025 or 1.026. Maybe @Randy Holmes-Farley can chime in here. I made some fresh salt water at 1.024 and added into my ATO. I am curious how many gallons it would take of 1.024 in my top off water to get my roughly 1100 gallons system back to 1.025 Salinity.

Let me know if there is anything else I should check or maybe it really was the lack of oxygen that was the issue with the RTN so quickly.

As always thank you for your input.