Trident & mastertronic testers - Why cant you cut/lengthen the tubes?


Plumbing Engineer
Im looking at getting an autotester and keep seeing notes about how you cant cut or extend the tubes on the units and I cant for the life of me figure out why?

They say its due to the pumps being tuned for it but I am literally a plumbing engineer and this makes zero sense.

If the pumps are calibrated for a tube length then any changes in elevation would have an impact as well. If they using peristaltic pumps as long as the line isnt clogged you get the same flow no matter what. If they are not peristaltic pumps the flow would not matter as you would need to operate the pump based on a level sensor. Either way the line length does not matter.

Can anyone shed some light on this?

Member No. 1

Ver. 2.1.1
Premium Member
When I was using a Trident, I shorten the waste line with no issues, readings were the same.
The supply line I would think can be shortened, but if they are using peristaltic pumps (which I believe they are) and are filling the chamber to a certain volume, lengthening the line might not allow any "dirty" or "stagnant" water in the line from getting flushed thru, so your reading might be off.

I am using a GHL KHD, and they allow you to vary the lines, within reason, and then you calibrate the doser based on the line volume.


Plumbing Engineer
Ahhh so its about the volume in the line being flushed out so you get a fresh sample. That makes a LOT more sense.

Ok so the sampling line should stay the same, RO inlet could easily be cut or lengthened without issues and the waste line could be shorter but longer may cause issues of stagnant waste from multiple tests mixing and who knows what that will do.

Maybe I will be able to get a mastertronic after all.