Hi,
my problem is in the title :)
First this is my tank:
It's a Eheim Proxima Plus aquarium, 320 litres (84,5 gallons) tank, about 200/220 litres net volume (52,8/58 gallons)
Eheim pump 1700 litres (449 gallons) per hour
Dennerle CO2 set with glass diffuser
Dennerle scaper's soil (on a...