Hi Darren, The ph graph looks like this after installing the additional FM100. So I would think another 0.05 increase in general? I have also made some other changes like increasing effluent and reducing my kalk dosage. So may not be entirely accurate representation of the effect. Oh. By the way, I also found out through a ph tank water airstone test, that my surface / tank aeration is too much compared to my ambient co2 levels in the room. Ie the co2 exchanges is happening faster than it can be removed sometimes. Made some changes on that too, ie increase aeration only during hours where ph of my tank is lower than an estimated ambient co2 levels. Sent from my iPhone using Tapatalk