RO/DI and TDS readings

[woochi]

Will your sediment and carbon blocks filters( stages prior the membrane), lower your TDS readings? My readings are 130 at water in from softener, then it passes through 2 sediment filters, 5 micron, then 1 micron. then the water passes through 4 carbon blocks 5 micron, 1, 1 and 0.6 micron. After all that my tds is still 130. The membrane removal is 128 tds and the di stages clear the rest. Are these readings normal?

 

[ReefFreak@]

I'm no expert but I'm pretty sure the sediment filter is just to catch particles like sand or other solid items that could ruin the ro membrane. I no carbon is used to remove chlorine and depending on your area chlromines. To me your readings look fine. Are you chewing thru pre filters and di resin?

 

[woochi]

My di resin seems to be going faster than normal , all filters, carbon blocks, di resin and membrane are New as of two weeks ago

 

[ReefFreak@]

What is your pressure, temp of the water, and rejection rate of your membrane?

 

[woochi]

59 degrees at start of ro filters, 65 psi right before the membrane( brs 75 gpd membrane with matching flow restrictor) 98% rejection rate

 

[woochi]

I'm thinking I need a pressure regulator , membrane is rated for 50 psi

 

[ReefFreak@]

i think its your temp. Thats really cold. I run mine at 78 79 degrees 65 psi isn't to crazy but if your worried instead of getting a regulator just upgrade to a dual ro membrane they need the higher pressure plus you get more water with better rejection rate. Another variable to think about is the tds coming into the unit. If your tds going in is 300 tds thats going to run out your preflight's faster than if its 80. One last question do you no if your source water has chlromines in it?

 

[woochi]

I don't know if I have chlromines but I do have a chlromine filter in it. How to I change the incoming temperature? Tds going in is 130 after the softener

 

[ReefFreak@]

Thats a good idea i run a chlorine filter as well. To no for sure just go to your water treatment plants website and you should find it. How is your unit plumbed?

 

[woochi]

I tapped into the cold water supply after the softener

 

[ReefFreak@]

i have mind hooked to the faucet temporarily but i think you could just have hooked to both the hot and cold water line.

 

[woochi]

I could use a temperature mixing valve for showers?

 

[ReefFreak@]

yes that would work fine. How long have your filters lasted? I replaced mine after about 4 months.

 

[woochi]

The sediment filters always look New unless the softener gets put on bypass because the discharge hose decides to pop off one day flooding the basement, but normally I'll do 6 months.

 

[ReefFreak@]

6 months is the recommended time to change your filters . Were you looking for longer?

 

[woochi]

Well forever would be cool but how long can you go? How do you know when carbon blocks are spent

 

[ReefFreak@]

I like to keep my water super clean so once i get a reading of 1 or 2 tds i swap out all filters, tds only measures tds not specifically what it is. They could be ammonia phosphates silicates list goes on, now I've heard of people stretching it up to 5-10. Im considering getting a second di chamber paired with the spectra pure max cap resin. A fellow reefer told me with that he has replaced them for a year and a half and still reading 0 tds!

 

[woochi]

Well my first 6 stages don't drop tds any, from what I can tell is the membrane and di resin take out tds, so a lot of di stages or better di resin could get you a year I would think

 

[ReefFreak@]

That my thinking to it lets the di resin after the first last a lot longer. why so many pre filters?Are you making a lot of water all at once?

 

[woochi]

I kept finding ro units on Craig's for free lol...I just kept adding stages because it was easy . It's overkill I know but it can't hurt. I do use NEW filters however