HMA Unit, when do you know when to replace filters

[Zebra Pleco]

Hi all, I have my RO and HMA unti connected up together, but looking the manuals, your meant to change the filters every xxxxx amount of litres used.

ooooops, I have a constant flow system running, trickles in mind you, so doesn;t use much. I will have to measure the outputs of the units.

But is there any other way to see whwn the ham unit needs replacing. I know the RO unit, I can just test the TDS, but unsure how to test the HMA?

Any help is appreciated.

Also can you get inline RO heaters for the push fit piping?

 

[macvsog23]

Never heat the water before it gets to the membrane.
Change your HMA / CRB filter every 4 months