Problem with GHL Doser - Appears to be dosing too much

AXBROWN · Apr 19, 2018

So one of the dosing pumps on my new GHL Dosing pump seems to be dosing too much... It says it has dosed 246 mL of my Magnesium solution from BRS, but when I look at container a little over 1/3 of the container is empty, which is more like ~800 mL. I have calibrated the pump multiple times, but I think something is going wrong. Any ideas? Did I program it wrong? I am attaching a screenshot of my programming.

(I had it set to dose 12 times per day at 4 mL per dose, for a total of 48 mL, it says zero now because I turned off all of the dosing)

Brew12 · Apr 20, 2018

AXBROWN said:
So one of the dosing pumps on my new GHL Dosing pump seems to be dosing too much... It says it has dosed 246 mL of my Magnesium solution from BRS, but when I look at container a little over 1/3 of the container is empty, which is more like ~800 mL. I have calibrated the pump multiple times, but I think something is going wrong. Any ideas? Did I program it wrong? I am attaching a screenshot of my programming.

(I had it set to dose 12 times per day at 4 mL per dose, for a total of 48 mL, it says zero now because I turned off all of the dosing)

When you calibrate the pump, how do you do it?

When I calibrate the pump I change the speed to something different than what I want and save it.

Then I set the speed to the speed I actually want and save it again.

Then I run the calibration.

A few other things you can check.

Do you have your dosing containers below the level where it drips into the tank?

How long have you been operating the pump before replacing the wear parts?

AXBROWN · Apr 20, 2018

Ive only had the pump for about a week, so it’s brand new, haven’t had to replace anything yet.

Yes the tanks are below the output hose.

I calibrate the pump by entering the preferred speed (1.3 mL per minute) and hitting calibrate.

I’ll try calibrating if your way tonight.

Any other thoughts?

kz4q66 · Apr 20, 2018

Select the preferred speed then SAVE then Calibrate then SAVE again.
After that do the manual dose to verify. Good luck.

Brew12 · Apr 20, 2018

AXBROWN said:
Ive only had the pump for about a week, so it’s brand new, haven’t had to replace anything yet.

Yes the tanks are below the output hose.

I calibrate the pump by entering the preferred speed (1.3 mL per minute) and hitting calibrate.

I’ll try calibrating if your way tonight.

Any other thoughts?

With new heads, dripping is unlikely (especially at that low dose rate) but it is worth watching to make sure the drips stop as soon as the dosing motor stops.

Right now I am kicking myself for my poor memory. I'm not sure if my Alk and Calc dosing is at speed 0 or speed 1. My calibrated flow rate is around 5mL/min. I thought it was speed 0 but I want to confirm that.