RODI UNIT what do i need?

[ddckec6972]

looking into a RODI unit, i have a TDS meter ordered so i can test my tap water, while i wait for it to arrive, I would like to debate which system is better and what TDS range would aid me in the choice.

4 stage----Perfect for city water that is treated with low amounts of chlorine, or well water with very minimal contaminants

5 stage ----handles most types of well water along with most types of city water treated with chlorine including small amounts of chloramines.

6 stage---- it contains excessive amounts of TDS or hard to remove contaminants like chloramines, phosphates, nitrates, silicates, etc.

theres alot out there about the RODI pros an cons but nothing i have found implies what the tds ranges of your tap water should be to aid in determining what type of system to buy, dont want to but a 6 stage set up if a four stage would work...Thoughts?

 

[JohnnyHildo]

personally I would ask a reputable ifs what they recommend based on what your tap water tests out to. there is no reason to buy a 6 stage when a simple 4 stage will fit the bill. either way, its a good idea to have a tds meter on the output line on the membrane and one after the last stage of filtration which will be your DI.
you want zero tds entering your system.

 

[aznflyfisherman]

I think a 4 stage is enough unless u really have bad water, plus u can always add stages to existing 4 stage rodi and make it 5 or 6 stage.

 

[alton]

You are pretty dead on with your list. I have high Chloramines which is worse than high TDS. I run a 4" x 20" carbon filter made for chloramines because my free and total chlorine is higher than what I keep my pool at sometimes hitting 4 ppm. So start with that test, you can buy the strips at your local pool supply that test for both. If you have high TDS go with a tested 99% RO membrane. If not that high most sell a 98% which is what I use, the lower your TDS is after membrane the less DI resin you will use. On DI resin one will suffice if you are johnny on the spot on watching your TDS, other wise use two and when the first one is spent rotate the old and place the new last. Water pressure needs to be 50 psi min. The higher the better, but if you add a booster pump and you have Chloramines the contact time thru the filters may not be enough and leak into your membrane killing it quickly.

 

[Opus123]

If you are on city water, you can usually get on their website and find the current water report which should have all the water parameters. The tds doesn't matter as far as number of stages to buy. As stated unless you have some high chemical levels, you are fine with a 4 stage unit. How a RO unit works, the first stage is a sediment filter and captures the larger particles so they don't clog your RO membrane. I would recommend a 1 micron size here, though I personally run a .2 micron size sediment filter. The second stage is the carbon block filter and this takes out all the chemical impurities from the water. I usually go with 1 micron here but you can do 5 micron if you want. So the sole purpose of the sediment and carbon filters is to protect the RO membrane from large particles and chemicals which would ruin the membrane. They have ZERO effect on tds levels. The RO membrane is what does most of the work of removing tds. My tap tds is around 450 and my tds after the membrane is 4. The DI stage then removes the remaining tds. Since DI is expensive and has a set amount of tds it can absorb, you want the tds going into it as low as possible.

 

[Zalick]

looking into a RODI unit, i have a TDS meter ordered so i can test my tap water, while i wait for it to arrive, I would like to debate which system is better and what TDS range would aid me in the choice.

4 stage----Perfect for city water that is treated with low amounts of chlorine, or well water with very minimal contaminants

5 stage ----handles most types of well water along with most types of city water treated with chlorine including small amounts of chloramines.

6 stage---- it contains excessive amounts of TDS or hard to remove contaminants like chloramines, phosphates, nitrates, silicates, etc.

theres alot out there about the RODI pros an cons but nothing i have found implies what the tds ranges of your tap water should be to aid in determining what type of system to buy, dont want to but a 6 stage set up if a four stage would work...Thoughts?

Call Spectrapure and they will tell you exactly what you need. Buy the unit from Spectrapure and buy their filters. They have the best units and filters in the business. They also have incredible customer service. Don't be fooled by other filters. 1 micron absolute is MUCH different than 1 micron nominal.

Scott at Spectrapure can look at your water and make a great recommendation. You can post in the sponsor forum and he will help you as well.