SpectraPure 90GPD - What filters to replace?


I'm an Addict.
Hi all, I've had my RO unit for about 4 months now, using quite heavily. I have probably ran about 1000 gallons through it.

I am noticing I am at about 45gpd now. I think its time to replace the filters.

What filters do I need to buy/replace?

I can't find much about this....

Anyone know?


New member
What is your TDS? We have 75 GPD and a 125. Doing 25% bi-weekly. Replace carbon and sediment every 6 months. RODI is replaced when TDS doesn't read zero. Bypass RODI and measure TDS from membrane. Measure TDS of straight tap. The water from the bypass should be 10% of the TDS from the tap or lower. Replace if over 10%. We've only replaced membrane twice in 8 years.
Condition of carbon and sediment will prolong membrane.


New member
I highly recommend to have the pressure gauge and a flush valve installed in your rodi.
I was able to extend the life of my filter twice as much buy flushing the system in a regular basis and the pressure gauge will help you identify when the filters r do to be change.


Premium Member
Often it is just the sediment filter that needs it.

You should be testing waste water for chlorine. You want to change them before chlorine makes it through. If at 6 months its still not making it through I would change the carbon blocks anways.

I would replace them to match their 90gpd maxcap system. Also check your waste to product ratio. It should be 4:1. If your supply water is colder due to being winter the unit will run slower.

You should be getting tds from the membrane that is less than 4% of incoming tds.
You should be getting 0tds from the first and last stage.