Lots of good options. I went with the GHL2, though I'd not judge it as all that easy to setup. Typical German over engineering.
Get three BRS dosers and three timers. Done and work very well.
The timer is for fail safe?
The timer is for the doser to know when to come on and go off. It is really simple. Figure out how much the doser puts out per minute and then figure out how much of the alk, calc, and mag you need to dose. If your doser puts out 1.5ml per minute and you need to dose 50ml of alk per day you would set the timer to comE on for 33 minutes a day. You can also split up the dose through out the day and do 11 doses of 3 minutes.
Get three BRS dosers and three timers. Done and work very well.
The timer is for the doser to know when to come on and go off. It is really simple. Figure out how much the doser puts out per minute and then figure out how much of the alk, calc, and mag you need to dose. If your doser puts out 1.5ml per minute and you need to dose 50ml of alk per day you would set the timer to comE on for 33 minutes a day. You can also split up the dose through out the day and do 11 doses of 3 minutes.
how do you find out how much you need to dose? (the 50ml a day)
GHL Doser 2 Stand Alone with 2 heads (can add one or two more later) is on sale for $305.
Once hooked up to MyGHL website it's extremely easy to set up and make changes. There is a mobile app too.
You get the rock solid engineering/firmware/build quality and GHL standing behind it.
Remember... a simple malfunction from a doser could cause you to wake up to a disaster.
Don't skimp.
That said, the suggestion for the BRS dosers on simple mechanical timers would also work and be pretty safe. It's just more of a pain to make changes.
I have both set ups on different tanks and eventually want to replace the brs setup with another ghl.
How would it do it any better then another quality unit.