question about rodi filters

[Prinz]

good evening,

 

test the tds of my ro unit today it came a lil high 25, so i guess its time to change filters, im just wondering if i have to change all the filter, sediment carbon and di, or just 1 or 2 of the filter,  i just dont want to waste a filter or 2 if it doesn't need to be change this time and/or how long does each filter last

 

thanks in advance

[ReefdUp]

I used to do what you're asking, and it's a bit of a pain to be honest. To do it right, you should have a pressure and TDS gauge before and after each stage. You'll have to monitor each stage and keep track of where the pressure and/or TDS starts to rise. You'll also need to calculate your RO rejection. It was a lot of work to save maybe a dollar or two every year on a decent sized system (was running about 1000g at the time). I was also recharging my own resin. Sure, it saved money, but my time quickly became more valuable.

[flooddc]

Whenever my rodi water is tested high (around 10). I replaced all the filters except the membrane. Sediment and carbon are cheap so, it’s better to replace them.

as for the membrane(s) the typical life is about 3 years. I always write a date on the housing of the membrane as a reminder. 

[Prinz]

1 minute ago, flooddc said:

Whenever my rodi water is tested high (around 10). I replaced all the filters except the membrane. Sediment and carbon are cheap so, it’s better to replace them.

as for the membrane(s) the typical life is about 3 years. I always write a date on the housing of the membrane as a reminder. 

do you change the di filter same time as the sediment and carbon?

[flooddc]

Just now, Prinz said:

do you change the di filter same time as the sediment and carbon?

Yes. 

Also, you can tell by the color of the sediment filter if it need to be replace.if it brown, then it’s time to replace.

[epleeds]

Are u running dual TDI with in/out or a single out?

 

when the last DI is expended the TDS will rise. When you have to replace that, you replace all 4. 

 

After replacing them all, you can replace 1&2 say 3-4 months in and it will extend the DI. 

 

I

[Prinz]

thank you all

[BtmDweller]

Final output should always be TDS zero. You can get color changing resin to make your life easier. If the sediment/carbon block is a tiny bit dingy I change them. Also, be aware sediment filters .5 micron or 1 micron. I use .5 .

 

There’s not a typical time to change filters. Lots of factors. Water coming in the system being one. Also, depends on the water volume you’re making. I’m changing DI fairly frequently 4-8 months. I’m making 250-300 gallons monthly and keeping TDS at zero.