You can set up the stand pipe so that one is a about 2-3 cm higher than the other, this will force the water to make a full siphon in one of the drain pipes, and then other drain pipe; you can adjust the return pump so that only a trickle goes down the other second drain pipe. This = silence! And very little loss of CO2 gas.
The second drain pipe acts as the unrestricted emergency overflow and also the slight trickle over flow.
The return pump's ball valve acts to regulate and dial in the exact flow to have just a trickle into the thr 2nd drain pipe. make sure there's about 3-maybe even 4-5 cm head pressure distance to get that single pipe flowing 100%.
So always buy a larger pipe diameter and larger overflow for your plant tank.
This will allow for more options and less degassing later.
Adjusting the stand pipe a little bit will make a lot of difference.
The second drain pipe acts as the unrestricted emergency overflow and also the slight trickle over flow.
The return pump's ball valve acts to regulate and dial in the exact flow to have just a trickle into the thr 2nd drain pipe. make sure there's about 3-maybe even 4-5 cm head pressure distance to get that single pipe flowing 100%.
So always buy a larger pipe diameter and larger overflow for your plant tank.
This will allow for more options and less degassing later.
Adjusting the stand pipe a little bit will make a lot of difference.