Kamoer SF-STP doesn't hold settings

[lost66]

I use Kamoer FX-STP on calcium reactor as an output and I set it as 7ml. After 24 hr I noticed lcd shows 9ml. 24 hours later 11ml.
Please advise, is it a defective pump, a known issue or I am doing something wrong?

 

[Snoopy 67]

The only thing I can think of is the spring loaded clamp over the hose could be loose & backing out allowing the ID of the hose to increase.

 

[lost66]

The only thing I can think of is the spring loaded clamp over the hose could be loose & backing out allowing the ID of the hose to increase.

Very good theory. Since it is a spring I have no idea how tight it should be. I will crank it up little bit and see.

 

[Snoopy 67]

Not too much 66