2 part dosing location

[Musicims]

Right now I have my kalk line (appx 150mL/min for 1.2min/hr every hour) and alk (sodium bicarb 1.45mL/min for 3.6min/hr every hour) line both about 3 inches into the sump terminating right in front of a small powerhead for mixture.

Is it better to have it this way or out of the water say right above the powerhead and drip in so that it is not in contact with water potentially diluting whats in the lines still in those first few inches before it even gets into the water column? Would the free air contact instead be better or worse?

 

[redfishbluefish]

I really can't comment on the kalk (calcium hydroxide) since I don't use it, but speculate that it doesn't precipitate in contact with tank water....so OK to submerge. However, the sodium bicarb (or carbonate) should be out of tank water and allowed to drip into the sump. Direct contact with tank water could cause precipitation.

I dose two part and both my dosing lines are out of water, and dosed into the return section of my sump.

 

[Hitman]

All my dosing line are 3" above water level with a power head 3" underwater blasting straight at the return pump intake.