Later in the week

[Craig Matthews]

Is it just me or does anyone else find that after a water change and upto about the 3rd day after the pH drop from injecting co2 happens quicker, maybe because the co2 present in the tap water? Later in the week say after 3rd day from water change the pH drop takes longer and longer as the week goes on even though injection rate and surface agitation hasn't changed?

 

[Luketendo]

Is it just me or does anyone else find that after a water change and upto about the 3rd day after the pH drop from injecting co2 happens quicker, maybe because the co2 present in the tap water? Later in the week say after 3rd day from water change the pH drop takes longer and longer as the week goes on even though injection rate and surface agitation hasn't changed?

Not for me. If you have your outlet near the surface of the tank and you don't top up evaporation then maybe surface agitation has changed. Saw in a Green Aqua video they had a tank with rim and outlet near the top effecting the CO2 levels a lot. When water touched the rim there would have been low agitation. Just an idea.

 

[Craig Matthews]

That's a fair point, I did think about it but I dont let the water drop anywhere near the top of the spray at but maybe a little evaporation makes a big difference.

 

[Luketendo]

That's a fair point, I did think about it but I dont let the water drop anywhere near the top of the spray at but maybe a little evaporation makes a big difference.

It should only make a big difference if you have a shallow tank or any factor impacting the water surface which changes a lot with evaporation - like tank rims or water outlet. Otherwise must be something else.

 

[JoshP12]

Hi @Craig Matthews,

I had an issue with exactly this before.

Basically, if I did not top the water up, then those micro drops would influence surface agitation so much that the drop would take longer.

My fix was to keep my water lower and closer to the output (so I had more surface agitation which led to higher injection rates which led to more stability; it also led to higher oxygen levels).

How much is your surface agitation after water change? If it is high, then it is something else (probably) but if it’s minimal, then I wouldn’t surprised, especially if it is a low injection rate.


Josh

 

[Craig Matthews]

Hi Josh, I have a very small ripple for surface agitation after water change but I do run a surface skimmer too so that in affect will/should increase the aggitation. I will keep an eye onit and yes I do seem to have a slight stability problem as in lights on oh is 7.36 and co2 off is 7.16 so a little Margine of error. Injection rate is high I cannot count the bubbles it's too fast. I've just turnt co2 up a little to try get that 7.16 for lights on . Will keep water topped up more often see if it helps. @Luketendo nothing breaks the water surface after evaporation only more surface ripple closer it gets to the spray bar so that may be it.