How bad is a yellow drop checker for fish?

[Cat]

I apologise because I'm sure this has been asked before but my search didn't bring anything up. I have been having CO2 problems for weeks, I either get a blue drop checker or a yellow drop checker, every time I try and tweak the CO2 over days it just doesn't budge. Meanwhile all the plants are dying and algae is going ballistic. So for whatever reason its currently very yellow. The fish seem fine, but does that mean they are fine?

It takes 2 days for the drop checker to turn yellow. I've had the tank for 10 years, never had so many problems with the CO2 and would rather keep it yellow so the plants can recover but obviously I have to think about the welfare of the fish.

We live in a hard water area, I don't use RO, I did for years couldn't cope with the waste. So it is what it is. Not sure if its relevant.

 

[Hanuman]

I have been having CO2 problems for weeks, I either get a blue drop checker or a yellow drop checker, every time I try and tweak the CO2 over days it just doesn't budge.

Did you check for gas leaks in the line? It could be that CO2 is escaping and only when you crank it up enough gets to the tank? Also, what method are you using to inject CO2? Inline? In-tank? reactor?

So for whatever reason its currently very yellow. The fish seem fine, but does that mean they are fine?

If you don't see them gasping around they should be fine but if the DC is urine yellow then you are probably reaching the limits of what the fish will be able to accep. You need to make sure the water is properly oxygenated.

It takes 2 days for the drop checker to turn yellow.

Not sure I understand here. Your CO2 is continuously open? If not, and if it really takes 2 full days for the DC to turn yellow this would indicate to me that there could be a poor gas exchange in the tank. Do you have a skimmer or is there enough surface agitation?

Please post some pictures of the tank so we can have a better overview.

We live in a hard water area, I don't use RO, I did for years couldn't cope with the waste. So it is what it is. Not sure if its relevant.

Not really because the DC is independent from the water in the tank.

 

[Libba]

What indicator fluid are you using? Did you use 4dKH water?

Obviously a yellow indicator can be bad for fish. The problem with a yellow indicator is that you don't know if its 40ppm or 70ppm, right?

 

[Cat]

Did you check for gas leaks in the line? It could be that CO2 is escaping and only when you crank it up enough gets to the tank? Also, what method are you using to inject CO2? Inline? In-tank? reactor?


If you don't see them gasping around they should be fine but if the DC is urine yellow then you are probably reaching the limits of what the fish will be able to accep. You need to make sure the water is properly oxygenated.


Not sure I understand here. Your CO2 is continuously open? If not, and if it really takes 2 full days for the DC to turn yellow this would indicate to me that there could be a poor gas exchange in the tank. Do you have a skimmer or is there enough surface agitation?

Please post some pictures of the tank so we can have a better overview.


Not really because the DC is independent from the water in the tank.

Hi thanks for your response, in answer to your questions -

-We've have checked for leaks and haven't found any.
-We are using a fire extinguisher with an inline diffuser.
-The Co2 is permanently open because we used to only have it on during the day, for the last 8 years in fact, but with all the problems we were having recently
we were worried water was permeating into the ceramic of the diffuser overnight.
-We don't have a skimmer, we have an inline pump feeding a spray bar with a fluidized bed and an external filter as back up on a separate system.
- I've attached a couple of pictures, its a big tank 420 litres.

 

[Cat]

What indicator fluid are you using? Did you use 4dKH water?

Obviously a yellow indicator can be bad for fish. The problem with a yellow indicator is that you don't know if its 40ppm or 70ppm, right?

Yes I'm using 4dKH. Theoretically I would have been able to check the solution with my Hanna pen but it currently its not working, might have to get a new one....

 

[Hanuman]

-We've have checked for leaks and haven't found any.

With foam?

-We are using a fire extinguisher with an inline diffuser.

its a big tank 420 litres.

Considering the size of the tank and the fact that your plants are pretty much overgrown I am not surprised at what your DC shows. The water flow is greatly disturbed by all those plants. If you have multiple DCs, place them at different locations. You will probably notice discrepancies in coloration due to poor CO2 distribution.
If I were you I would do a good trim and see how it goes from there. I would also clean the ceramic in the diffuser. Also, a CO2 reactor would probably be more suitable for your tank size. There is a lot of CO2 loss with diffusers, even more so if the said spraybar is pointed slightly upwards which off gases CO2 pretty fast.

we were worried water was permeating into the ceramic of the diffuser overnight.

Not an issue if the ceramic wets during off time. It's expected.

 

[Cat]

With foam?


Considering the size of the tank and the fact that your plants are pretty much overgrown I am not surprised at what your DC shows. The water flow is greatly disturbed by all those plants. If you have multiple DCs, place them at different locations. You will probably notice discrepancies in coloration due to poor CO2 distribution.
If I were you I would do a good trim and see how it goes from there. I would also clean the ceramic in the diffuser. Also, a CO2 reactor would probably be more suitable for your tank size. There is a lot of CO2 loss with diffusers, even more so if the said spraybar is pointed slightly upwards which off gases CO2 pretty fast.


Not an issue if the ceramic wets during off time. It's expected.

Thank you for all your advice. We did a leak check by painting washing up liquid and previously found a leak around the bubble counter in our old diffuser which we replaced.

I'll buy some more drop checkers and trim everything like you suggest. We've actually just finished making a reactor we just need a bit of child free time to install it so hopefully that will help too

Thank you for help!