Red Sea Liquid Dosing Bottles - Tubing?

[RaymondL]

Instructions in Red Sea's dosing liquids it says to use a 5mm inside diameter tube inside the bottle, and 4mm inside diameter tube for outside spout. Red Sea tubes for sale are 3mm - I'm confused.

 

[billyocean]

The bottom of the bottle cap (inside the bottle) needs a bigger line/tube attached to suck out the fluid. The top of the bottle requires a smaller line/tube that runs to the doser. So the 5mm tube is on the inside. 3mm tube attaches to outside

 

[RaymondL]

The bottom of the bottle cap (inside the bottle) needs a bigger line/tube attached to suck out the fluid. The top of the bottle requires a smaller line/tube that runs to the doser. So the 5mm tube is on the inside. 3mm tube attaches to outside

Thanks - I think I misread the instructions included in the dosing bottle. 5 mm and 4mm is the outside diameter, so in reality, 4mm and 3mm tubing is needed. I believe 5mm is standard airline tubing, and 4mm is commonly found with dosers - as a matter of fact, some were provided in my doser when purchased.

 

[billyocean]

I have kamoer doser which was 3 so yours may be different. Don't know why they don't just make them the same size? Maybe some dosers are 5 mm tubing and it's better to be too big than too small?