Dosing with 30 minutes difference?

[almost]

I am using timer 28 to dose Magnisium: 24 dosings per day / 5ml per dose / every day (flow rate 41ml/minute).
I am using timer 32 to dose kH: 24 dosings per day / 13 ml per dose / every day (flow rate 43ml/minute).

I need theese products to be added with 30 minutes from each other.

How can I do that?




**My other dosing pumps acts like this:
Timer 25: Manu.dosing 4ml at 15:00
Timer 26: Auto dosing 1 dosing per day / 1ml per dose / every day (flow rate 55ml/minute)
Timer 27: Auto dosing 24 dosings per day / 3ml per dose / every day (flow rate 42ml/minute)
Timer 28: See above
Timer 29: Manu.dosing 15ml at 12:00
Timer 30: Manu.dosing 8ml at 21:00
Timer 31: Manu.dosing 6ml at 14:30
Timer 32: See above

[almost]

Any ideas?

[Wirus]

Possible would be (not tested)

increase of timer 28 to 48 dosings (all 1/2 h)
increase of timer 32 to 48 dosings (all 1/2 h)
new timer with programm "cyclic", "min. wait time" of 1800s and also a "max. wait time" of 1800s
new programmable logic1, function AND with input1 timer 28, not inverted, not delayed and input2 the new timer, not inverted, not delayed
new programmable logic2, function AND with input1 timer 32, not inverted, not delayed and input2 the new timer, inverted, not delayed
assign new programmable logic1 to Magnisium socket/dosing pump
assign new programmable logic2 to kH socket/dosing pump

The function is as follows: The dosing units try to dose all half hour, but only one of the two can dose due the cyclic timer allows only one to be active.