Hi all.

It's been a busy couple of weeks on my new tank whilst I modified my sump.
I've enlarged the initial chamber, put a sock filter in there and covered it up to get a nice gastight seal. The access port to get at the filter is a glass panel with some rubber seals which seem to work just fine.

What I have is a 900 Lph pump driving into a Mazzei injecter. This then passes through a UV unit and into the intake of the return pump, a 3500Lph.

I fitted the return chamber cover with a 6mm pipe which I have fed to the intake of the first pump. When it's in place it's pulling the gases (which I assume to be a mix of CO2 and atmospheric gases) from the chamber into the pump but it's appearing in the tank as large bubbles; I assume the atmospheric gases are not as soluble?

I'm still struggling to get a good level of CO2.

I can see a nice mist of CO2 but my drop test is a darker green and my pH is around 7.0 - 7.1. KH is around 6-7.

Just a question, CO2 in water drives down pH; can the same be seen with CO2 in gas phase? As it's still a gas it won't have mixed with the water.

Any thoughts? I now have everything ready but I don't want to plant the tank until I can get CO2 working effectively.