CO2 overload...fish stressed.....why?

[oldbloke]

Did my usual 50% w/c today.
I also changed my light timers to 90 mins earlier.
So......

WAS....

Co2 on 1500
Lights on 1730

TODAY...

CO2 on 1500
Lights on 1600

2100, fish really struggling for oxygen but only in ONE of the tanks. The other one is fine.

Drop checkers nowhere near yellow.

What happened?

Cheers.

 

[Martin in Holland]

Your drop checker only checks the PH not CO2 level and this can give a wrong indication, KH and GH have an effect on you PH so even though that in one tank all is good doesn't mean it should be the same in another tank and as you know, fish don't care that much about PH...
But did you check for Nitrites, cause this can have a similar effect on fish?

 

[oldbloke]

Thanks Martin.
No I didn't check for nitrates. To be honest I can't really think why they should have rocketed in one tank?
I banged a few litres of fresh water in and they soon looked ok and all is ok this am.
Still don't really understand it.

 

[pepedopolous]

Hi,

If you use proper drop checker solution the GH and KH of the aquarium water is irrelevant. The bubble of air in the drop checker means that only CO2 from the aquarium water can diffuse through into the drop checker solution.

The colour change is as a result of CO2 reducing the pH of the drop checker solution. Therefore, it does indicate the level of CO2. The only problem is that the reaction is slow so it only shows the CO2 level from an hour or two previously.

As long as you use proper drop checker solution and don't use aquarium water to make it, it is a useful indication of CO2 levels,

Here's a link about drop checkers with more info: -

~Explanation of how a drop checker works~

Apart from that, I don't know what happened as if both of your tanks are cycled and not overstocked, nitrites should not be an issue. Even if nitrites were too high, the solution would be more water changes!

Cheers,

P

 

[Martin in Holland]

hi Pepedopolous, your right but as you know, many of us use water from the tank which can have different levels of GH and/or KH...
any way I wonder what could be different in one tank from the other that gives this kind of problem to the fish....

 

[oldbloke]

Hi,

If you use proper drop checker solution the GH and KH of the aquarium water is irrelevant. The bubble of air in the drop checker means that only CO2 from the aquarium water can diffuse through into the drop checker solution.

The colour change is as a result of CO2 reducing the pH of the drop checker solution. Therefore, it does indicate the level of CO2. The only problem is that the reaction is slow so it only shows the CO2 level from an hour or two previously.

As long as you use proper drop checker solution and don't use aquarium water to make it, it is a useful indication of CO2 levels,

Here's a link about drop checkers with more info: -

~Explanation of how a drop checker works~

Apart from that, I don't know what happened as if both of your tanks are cycled and not overstocked, nitrites should not be an issue. Even if nitrites were too high, the solution would be more water changes!

Cheers,

P

It's the same checker with the same fluid on the same co2 bottle and so on...!!
Just don't know what happened but I will be home today to monitor it all,,,!!

Thanks all.