I was very hesitant about buying this dosing pump after reading some pretty terrible reviews. Even many of the positive reviews stated there were issues. Maybe I am very lucky (and I'm going to keep my fingers crossed), but through all of my initial testing everything is perfect! When I first opened the box I was a little underwhelmed with the quality of the casing. However, given the price, that's perfectly fine. When it came to actual use I was very happy. I quickly figured out how to navigate the menus and set timers with my desired dosages. All pumps worked out of the box and the calibration was spot on! I am now hooking up to my system and really hope to have success in the long term

Iv read that there is certain models like version 1 and version 2 mine I received was grey in color calibrated to 100 ml the dosing would be inconsistent between 4 and 10 ml off each time contacted seller and they shipped me a new control circuit and this one was black in color calibrated it to 100 ml and now it's just off 1 ml each time will review it again in 3 months.

Works great. Was a bit worried due to mixed reviews. So far so good. Supper easy to dial in. It's pretty self explanatory. Good doser for the price. Love it so far!

First, the Verdict:
It is OK, and just OK, barely passable 3 Stars. It might work well, with some significant amount of time invested in making sure the pump actually pumps the correct amount of liquid. Because to me the margin of error is a bit to high for the application.

Now the reason, the Good, the "OK" and the "Bad"...

The Good:
The Price, it is not exorbitant for a unit that can deliver what it promises, and that is pump nutrients, or food to the corals, etc.

The OK/Can Live with it:
The instructions are clearly translated from Chinese, so for those of you who are maybe surprised by the broken English in the instructions, my recommendation is to re-read it a few times. Eventually you will get it. Or go watch videos online of others who set it up.

The Bad/Or I should Say, less than Perfect:
Pump is NOT precise by any stretch of imagination. The margin of error, even if you set it up correctly with proper 100ML/to Rotation Ratio and so forth, is about 10% to 15% which, when it comes to pumping a fertilizer into a tank which is less than 100 Gallons can be problematic. Since you will either under-fertilize, or sometimes over fertilize the water column. I will continue to play with it, to see if I can find this particular perfect pump ratio. But, I have used graduated beaker to exactly measure the 100 ML/to Calibrate the pump - yet, every single time I have run some pump tests, the pump will either under deliver by 10%-15% or overdeliver by the same amount. It is worrisome. One time one of the pump heads delivered 2x/200% of the amount for whatever reason, while the settings were triple checked.

Was directed away from this pump and toward more expensive models from friends and employees and the LFS. This is one time that I am glad I ignored the advice. The pump has performed perfectly since installation and the parameters of those being dosed have never been so stable. I would not hesitate to recommend this to any friends and family! Great deal and works perfectly!