CO2 1 pH drop and aquasoil

[artaqua]

Hello,

First of all I really love this forum and it helped me a lot in my aquascaping journey.

However, i'm struggling to have a clear answer on a point :
I read many times that the sweet spot of CO2 injection is a 1 pH drop.
But, is that really achievable when using an aquasoil that buffer KH/pH ?
In my case, i'm using the Tropica Aquasoil (pretty new, nearly 2 months) and even with an high injection rate my pH seems to be stuck at ~6.

I will love some clarification on this point when using buffering soil.
Thanks in advance for your help

 

[Zeus.]

Aquasoil (AS) with its Cation exchange capacity (CEC) buffers the tanks nutrients and pH, there can be a decrease in pH with some AS and this is normal. This drop in pH can be beneficial esp when your tap water is on the hard side as the decrease can improve the Fe availability to the plants.
When it comes to injecting CO2 however I have never heard of issue or had one myself and I have used AS and managed a 1.0pH+ without an issue.
As for high injection rate here a vid of my injection rate in my 500l tank

I use to adjust the working CO2 pressure to adjust the injection rate as counting bubbles seemed fruitless

The colour change of the Drop Checker (DC) is the best indication of [CO2]

 

[Bradders]

I had this 'problem' as well. Tap water was pH7.6, aquarium water with Tropica Aquasoil was pH7. So where is the 1pH drop?

In the end I done two things:

1. Took the average between the aquarium water and the tap water. (pH 7.3, so aimed for pH6.3 for 1 pH drop method).
2. Used my Dropchecker to ensure it was lime green when reached pH6.3 (i.e. not too little, not too much).

The drop checker is the important part, as the 4dKH solution separated by an air gap from the water. The CO2 has to cross the air gap so you know its measuring CO2 without having to worry about the pH of the water.