Which BRS RODI Unit - 4 or 5 stage?

Jake029 · Jul 15, 2018

Which BRS RODI unit should I get? The 4 stage value plus or 5 stage value plus?

I live in a city so I think the 4 stage is ok but any reason I should get a 5 stage?

theMeat · Jul 15, 2018

5 stage on city water so you can run carbon.
On well water 4 is usually enough

RavenSF · Jul 15, 2018

Check out BRS’s YouTube channel, they have done at least one video on RODI units. I have good city water, but always seem to grow algae very easily. I just ordered the BRS 7 stage unit after watching their video on it to rule out a water issue.

Reefiness · Jul 15, 2018

I just got a 7 stage too after it came out. I like having the ability to change out each di resin individually

Jake029 · Jul 16, 2018

Uhh...I'm reading that the more GPD means less efficiency. Does that mean a 75 gpd is preferrable over something like 100 gpd?

Bruno516 · Jul 16, 2018

The higher GPD just means higher flow rate really. Filtration is important in a system and you want to make sure you get a system that can handle your water conditions. Some people are in high sediment areas, so they have 2+ sediment filters, some people have high chloramines so they use extra carbons or chlorplus, and some people just have clean water and get away with a 5 stage RODI sediment-carbon-membrane-DI(roughing stage)-DI(polishing stage).

Another important factor in the system is accessories. Having a pressure gauge is nice and will give you an idea when to change pre-filters(drop in pressure), TDS meter will provide you all around water quality control (when to change DIs and membrane), an auto shut off valve + float valve will automate the filling of a reservoir, manual flush for flushing down "TDS"Creep."

Buckeye Hydro · Jul 16, 2018

Guys - there's a fair amount of "not-quite-right" info in this thread. So people don't get confused I'll post some clarifications.

I live in a city so I think the 4 stage is ok but any reason I should get a 5 stage?

If you don't have chloramines in your water, 4 stages will likely be fine.
http://www.buckeyehydro.com/premium-rodi-system/

5 stage on city water so you can run carbon. On well water 4 is usually enough

There are common cases where this is not correct.

Buckeye Hydro · Jul 16, 2018

I'm reading that the more GPD means less efficiency. Does that mean a 75 gpd is preferable over something like 100 gpd?

Higher gpd membranes are not less efficient if you're talking about the amount of feedwater that becomes RO or DI water. In the absence of water quality information re your feedwater, you'll want to run any residential RO membrane at about 20% recovery (the proverbial 4:1 ratio you've probably heard of).

Buckeye Hydro · Jul 16, 2018

Another important factor in the system is accessories. Having a...manual flush for flushing down "TDS"Creep.

There's some confusion here regarding the difference between a DI BYPASS and a FLUSH VALVE. Using a flush valve to address TDS creep isn't the way to go. A DI Bypass valve does that very efficiently.

A FLUSH VALVE is installed as a bypass around the flow restrictor on the concentrate ("waste water") line. http://www.buckeyehydro.com/membrane-flush-kit/
A DI BYPASS VALVE temporarily routes the permeate ("RO water") to a drain rather than to the DI as a way to address TDS creep. http://www.buckeyehydro.com/tds-creep-bypass/

Russ

Billdogg · Jul 16, 2018

Thanks for chiming in Russ!

Your excellent customer service is exactly why y'all are my go-to for all my ro/di needs. (And it looks like I'll be ordering a complete set of filters for my 4 stage soon. I looked at the piece of tape I use to mark the change out date the other day - would you believe March 2016? )

Buckeye Hydro · Jul 16, 2018

Billdogg said:
Thanks for chiming in Russ!

Your excellent customer service is exactly why y'all are my go-to for all my ro/di needs. (And it looks like I'll be ordering a complete set of filters for my 4 stage soon. I looked at the piece of tape I use to mark the change out date the other day - would you believe March 2016? )

Sweet mother of pearl! I think it's time. I'd sanitize it before you put new filters in.
http://www.buckeyehydro.com/content/Sanitizing_RO_RODI.pdf

lion king · Jul 16, 2018

@Buckeye Hydro is right, check out your city's water website to see if they use chloramines. If they use chlonmines then a 5 stage would be in order, if not, a 4 stage is fine; I've used a 4 stage for many years with great results and satisfaction.

PatW · Jul 16, 2018

I have a BRS 6 stage 75 gpd. The stages are sediment filter, 5 micron carbon block, 1 micron carbon block, RO filter, then 2 DI canisters in series. That way, I can fully deplete a DI canister and still have 0 tds water. My city water is chlorinated but not chloamines. It has a tds of about 140. My tds is 2 coming out of the RO filter. My water pressure is about 65 psi. It is fine for the RO filter and it does produce about 75 gpd which is academic because my RO storage is a 44 gallon Brute trash can.

The advantage of the 7 stage system is you have three kinds of RO resin. One for, I believe, cations, the other for anions and one mixed bed. I have toyed with the notion of adding a canister and going to seven.

Buckeye Hydro · Jul 16, 2018

What is the micron rating on your sediment filter?

KStatefan · Jul 16, 2018

Buckeye Hydro said:
There's some confusion here regarding the difference between a DI BYPASS and a FLUSH VALVE. Using a flush valve to address TDS creep isn't the way to go. A DI Bypass valve does that very efficiently.

A FLUSH VALVE is installed as a bypass around the flow restrictor on the concentrate ("waste water") line. http://www.buckeyehydro.com/membrane-flush-kit/
A DI BYPASS VALVE temporarily routes the permeate ("RO water") to a drain rather than to the DI as a way to address TDS creep. http://www.buckeyehydro.com/tds-creep-bypass/

Russ

There must be a lot of miss information out there about flush valves this seems to come up regularly.

Buckeye Hydro · Jul 16, 2018

Yes - I need to copy it so I can paste it next time it come up - which it does frequently.

lordraptor1 · Sep 22, 2020

i have to chime in here for a minute, im running an old kent marine maxxima Hi-S unit although no hi-s membrane and it is a 4 stage unit. well the water in my city is chloramine and i have never had an issue with my unit in any aspect and change my prefilter when it looks dirty, my di resin when it is spent, and my carbon filter as recommended by the carbon supplier and my membrane i change every 2 to 3 years ( usually around the 2.5 year mark). not sure where all teh chlorine, chloramine stuff came from but i am usually still getting 0TDS when i change filters.

with that said, i also dont have any issue with a few phosphates, nitrates or iron from ro unit since i use an algae scrubber but i do wonder based on my personal experiences with my rodi unit why people say you need 5 stages to run extra carbon stage or you need to run chloramine filters?, is this just something manufacturers have done to get you to pay more money for a filter listed as chloramine ( which i use a single standard carbon filter in my unit BTW) or is it just some magic of my old kent marine unit that makes it superior to all currently made and in production units.

FYI this is no joke im being serious.