What is the best RO membrane

Advice wanted please.  

I’ve been on the Windows for 4 years, Water now reading 0.080ppm out of the RO so time for a new membrane?

I have super high pressure and use about 3000l per week. Tap TDS is about 0.300-0.350ppm. My membrane housing is 40/40 40inch long

I was thinking axeon hf4? Any suggestions or anything else I should consider? 

Thanks in Advance!

Aexon yes, but HF4 would depend on your water pressure.

Look on Gardiner website for recommended usage pressures for HF4 and HF5.Our HF5 Aexon has been faultless for 6 years now and still producing pure at a 98% rejection rate with 50psi. Granted our tap water tds isn't as high as yours at between 99 and 147ppm.

I would recommend a HF5 as mine fills a 500litre from empty in around 2 hours at 42PSI - Anything over that PSI will just bring the PPM down.