stages needed on RO for reef tank

TNL8108 · Mar 8, 2015

I have always bought my RO when I needed it but, after upgrading to a 220 gallon tank we decided it's best to make our own. How many stages do I need? The pet stores say 5-6 stages but the research I find all say 4-5. Can anyone help me?

Rjramos · Mar 8, 2015

I have six stage;
1 sediment
2 and 3 carbon block
4 100 gal/day r/o membrane
5 in line carbon final filter
6 DI resin filter

Rob.D · Mar 8, 2015

Welcome to Reef2Reef!!!

I run a 5 stage
1. Sediment
2. Carbon Block
3. Carbon Block
4 Dual 75 gph RO
5 DI Resin

Windy · Mar 8, 2015

You have to consider the water. Get a TDS Meter and check your incoming tap water. For example my water is quite clear and I have TDS of 23 before any filter. I then use a sediment filter and then a carbon filter prior to the RO membrane. Nothing after that, and I have zero TDS on exit. I could add another carbon filter or DI unit, but to what benefit?

Reefing Madness · Mar 8, 2015

Moved to curent location.

TNL8108 · Mar 8, 2015

Thanks! Any suggestions on a brand? I found a six stage on Amazon for $130. Made by LiquaGen.

Windy · Mar 8, 2015

Never heard of them.

Rjramos · Mar 9, 2015

Good deal! Names don't matter it's all the same.

TNL8108 · Mar 9, 2015

Could I get away with a 4 stage or should it stay a 5+? I found a 4 for $90.

NanaReefer · Mar 9, 2015

I've been running a 4 stage for 5yrs. Works great!

AZDesertRat · Mar 9, 2015

The number of "stages" doesn't mean a hill of beans. It is wha teach stage contains that matters so make each of the 4 necessary stages as efficient as possble.
A properly designed RO/DI will contain one 1 micron or smaller sediment filter and absolute rated or near absolute is better than nominal rated. One 1 micron or smaller carbon block and 0.5 or 0.6 microns is better but can always be added at the first 6 month filter replacement. One 75-90 GPD RO membrane. Dow Filmtec is by far the most popular choice here and the standard of the industry. And finally one full size vertical 20 oz refillable DI.

Other things you will want to look for are an ATC handheld TDS meter such as the HM Digital TDS-3 or TDS-4TM, an inline pressure gauge to help troubleshoot the sediment and carbon filter conditions and a capillary tube flow restrictor you the end user can adjust to match your exact water conditions.

This is by far the best value in a reef quality RO/DI there is:
Refurbished 90-GPD RODI System

I would also recommend looking at the Premium 75 GPD systm from Buckeye Hydro and the Optima series from PurelyH2o. The one in the photo above is pretty low end as evidenced by the opaque housings and small horizontal tubes they call DI.

NO RO by itself will evr produce 0 TDS water, it is not possible. A RO membrane is a 90-98% efficient device and is not particularly good at removing some things so acts as pretreatment for DI or deionization which polishes off what the RO misses.

LILBUDDHA · Mar 9, 2015

I used a 7 stage unit but 5,6 would have been fine . City water ,so gac n carbon block are a must have for me.
1.sediment filter
2. sediment filter
3 gac carbon
4. carbon block
5 .75 gpd membrane
6 di
7 di

I prefer all clear cannisters . A pressure gauge helps but is not a must have . A dual inline tds meter is very helpful . I like the SP units when refurbs are on sale but the shipping makes it not a great deal . It's weird because u can get free shipping , 15.00 shipping or get hit with a 44.00 shipping rate . So shop around.
I am not a fan of those torpedo di canisters .Some are refillable and some are not . Most are 2 inches in diameter and I am pretty sure the refillable ones that fit in a normal canister hold more media .

Windy · Mar 9, 2015

I have a 29 stage unit..................................:yo:

AZDesertRat · Mar 10, 2015

GAC has no place in a reef RO/DI. Its only use is in drinking water systems as a post RO taste and odor filter. GAC before the carbon block is totally worthless after 300 total gallons of water and 1 mg/L chlorine residual, that is 60 treated gallons and 240 waste gallons at thenormal 4:1 waste ratio, it does nothing after that but take up canister space. A single 1 micron carbon block lasts up to 12,000 gallons (2,400 treated-9,600 waste) and a single 0.5 or0.6 micron carbon block lasts 20,000 gallons(4,000 treated-16,000 waste). Don't waste your money on GAC.
Two sediment filters can also be a detriment unless you have silt or particulate problems and use the first filter as as a sacrificial filter. Everything you addin front of the membrane can cause headloss reducing the efficiency of your RO.
A pressure gauge is a necessary tool, it is one of only two or three things we have in our arsenal to monitor condition. Pressure drop due to plugged or fouled filters, chlorine breakthru dueto exhausted carbon and TDS or conductivity from a bad membrane or DI, thats about all we have to work with so the gauge is necessary.

A standard refillable DI cartridge holds 20 oz of resin when properly packed. Most horizontals hold 9 to 12 oz with some 16 oz. The problem is they lay flat so the RO water takes the path of least resistance along he bottom and short circuits or channels so poor treatment. The verticals fill from the bottom and exit the top so all resin and water come into contact with each other.

LILBUDDHA · Mar 10, 2015

AZDesertRat said:
GAC has no place in a reef RO/DI. Its only use is in drinking water systems as a post RO taste and odor filter. GAC before the carbon block is totally worthless after 300 total gallons of water and 1 mg/L chlorine residual, that is 60 treated gallons and 240 waste gallons at thenormal 4:1 waste ratio, it does nothing after that but take up canister space. A single 1 micron carbon block lasts up to 12,000 gallons (2,400 treated-9,600 waste) and a single 0.5 or0.6 micron carbon block lasts 20,000 gallons(4,000 treated-16,000 waste). Don't waste your money on GAC.
Two sediment filters can also be a detriment unless you have silt or particulate problems and use the first filter as as a sacrificial filter. Everything you addin front of the membrane can cause headloss reducing the efficiency of your RO.

Thanks ,
I didnt mean to say GAC . It's proly CC, the blue top and bottom cartridges .Some were white . The name pentek comes to mind . I just bought what the local lfs had on hand and advised . Never tried to buy the refillable ones . I figured I would this time . SIGH
It was a Kent maxima unit married to a Kent D unit ( had both since 2000 ish ) .I did use two sediments and it worked fine . We had a lot of sediment . I changed them a lot . I had crazy head pressure and they had to turn it down . I have used those 20,000 blocks and they were Meh , didn't see too much of a difference either way . As long as my end product water was 0 tds , I felt it was good to go . Product water output was consistent except winter time . I donated the unit to a newbie in the hobby so I am looking for a new unit now .

As u can see the sediment got quite dirty quickly .Wasn't even a month's use on a nano build when the ro/di was set back up . Can't complain the units lasted forever except changing filter's, membranes and flow restrictors as needed .

AZDesertRat · Mar 10, 2015

Get a $5 low range chlorine test kit and test for chlorine breakthru after the CC or GAC and you will see it exhausts very quickly so is not a good value. Discoloration of the sediment filter does not necessarily mean it has headloss but it takes a pressure gauge to determine this and is why most reef systems have them. Before my local wate rutility switched from groundwater to surface water we had discoloration too but the filter would still go the 6 months without significant pressure drop.

LILBUDDHA · Mar 10, 2015

AZDesertRat said:
Get a $5 low range chlorine test kit and test for chlorine breakthru after the CC or GAC and you will see it exhausts very quickly so is not a good value. Discoloration of the sediment filter does not necessarily mean it has headloss but it takes a pressure gauge to determine this and is why most reef systems have them. Before my local wate rutility switched from groundwater to surface water we had discoloration too but the filter would still go the 6 months without significant pressure drop.

Thanks Again.
Will do . Back to looking for units . I wanted a 90 gpd UHE but they don't seem to address Chlorine break through . Or does it ? The choices get complicated . My TDS is 160 at the tap Hanna TDS handheld with a 1.36 PPM Phos ( hanna ) . I haven't picked up a Chlorine test kit but I will . I am not willing to live with a 3 +1 rejection rate since we get hit over the head with water usage imho .

AZDesertRat · Mar 10, 2015

The UHE-100 uses a 0.2 micron absolute rated sediment filter and a 0.5 micron extruded carbon block that is more than capable of removing the chlorine portion of chloramines and breaking the bond with the ammonia which gets removed by the membrane and DI. One big key to carbon effctiveness is protecting it with an equal sized or smaller micron rated sediment filter so the pores in the carbon where the chlorine is adsorbed do not become plugged or fouled. I use two pressure gauges to monitor incoming pressure and pressure after the carbon block and a low range chlorine test kit to monitor breakthru as well as a COM-100 handheld TDS meter to monitor membrane and both DI cartridges performance. By doing all that monitoring I am able to stretch filter replacements to over 18 months with no loss of performance at a great savings.

Phoenix does not use chloramines but I have been using the UHE for 7 years now with excellent results and can count the total number of filter and DI replacements on my hands without having to take my shoes off. Amazing system.