how can i test dissolved 02/co2 levels in tank

[dj synystr]

i have recently had a loss of 5 tnags overnight from what i believe was a lack of 02 in the fresh water i put into the tank for a water change. do you know of any test or test kits i can do to figure this out. thanks in advance.

 

[bertoni]

There are some O2 test kits available. I've used the Salifert test kit. I don't know of any CO2 test kits that will work in saltwater, although there might be one.

How much water did you change? I would think a very large change would be required to kill 5 animals due to oxygen deprivation. Does the tank have a skimmer?

 

[Randy Holmes-Farley]

How much water did you change? I would think a very large change would be required to kill 5 animals due to oxygen deprivation.

I agree that seems unlikely.


Any reason to not aerate it in advance?

There are O2 kits and meters (meters are very expensive), but CO2 isn't something worth measuring in seawater.

 

[Boomer]

I have done 95 % water changes and nothing dead in 30 years of doing it. Fresh water changes usually raise the O2 not lower it.

Did you have any kind of power loss/falilure ? There are no kits that can measure CO2 in seawater. Most tanks only have not much more than or less than 1 ppm CO2. Even a very high Alk will give about 2 ppm CO2

 

[dj synystr]

normally i do a 5 to 10 gallon water change and never worried about aerating the ro water. this time i did a larger 15 to 20 gallon change due to the fact i havent done one in a while. yes i have a skimmer. the thing is i got ride of all my micro bubbles by adding a baffle in the sump, along with the water change, and the lights going out had to of all combined to cause the lack of o2 in the water collum. and no there were no power outtages, someone was here the whole time.

 

[Randy Holmes-Farley]

But the deaths could have been to to numerous other things besides O2. Ammonia, chlorine, chloramine, temperature change, etc.

 

[dj synystr]

i checked ammonia, nitrates, nitrites, ca, ph, alk, temp, phosphates and everthing was well within the "normal" readings for an established tank. but in the other forum everyone insisted it was an o2 problem.

 

[boxfishpooalot]

I also suggested that it could be from a form of phosphate remover that you change quite frequently and that some kind of phosphate remover was said to kill tangs.

I think we can take the ammonia off the list because only tangs were effected, while other fish were not. Unless tangs are perticualry ammonia sensitive. But that would be a crazy interpretation.

 

[Randy Holmes-Farley]

ammonia, nitrates, nitrites, ca, ph, alk, temp, phosphates and everthing was well within the "normal" readings for an established tank.

Of those, only ammonia is a significant concern WRT dead fish, except temperature, which might have risen or fallen rapidly, then returned to normal but I expect that is unlikely.

Chlorine? Chloramine? From you top off water or water change water?