School me on RO/DI

[whyamisofly]

I have been out of the hobby for a while and it looks like things have changed in the RO/DI world and I have also forgotten what I learned in the past.


There are a couple local reef clubs with used RO/DI units for sale.

One is a Aqua FX 100gpd RO/DI with booster and Auto Flush that needs all new filters. ($250)

One is a no name 5 stage RO/DI that also comes with an extra dual di set up (1 year on the filters). ($100)

Or I could purchase a new Spectrapure MaxCap 2:1 Manual Flush 90-GPD RO/DI System ($320) as well. I am looking to have a minimum of 2:1 (would prefer 1:1), but don't want to be replacing filters/membranes/etc because of the water saving. I'm not quite sure I need a booster pump (unknown water pressure currently) as I'm not sure how it helps. Before I left the hobby previously, Spectrapure was the "best" RO/DI on the market - now I'm not sure.

I could purchase the used no name RO/DI, replace the filters/etc with Spectrapure and add a second RO to bring it down to 2:1.


Can someone help me out?

 

[Reef Frog]

The greatest difference in quality & performance is in the filters and Spectralure is considered among the best, especially the RO membrane itself. It rejects smaller particles than most other membranes. Some sediment filters have different

Booster pumps are highly recommended for water pressure below about 60 psi. This helps the RODI unit achieve its maximum efficiency.

 

[jabudda]

Bulk Reef Supply makes fantastic units for reasonable prices.

 

[dkeller_nc]

Bulk Reef Supply makes fantastic units for reasonable prices.

Yeah, you'll pay considerably less than $320 for "deluxe" unit from BRS - like this one.

 

[whyamisofly]

Thanks for the replies everyone.

Yeah, you'll pay considerably less than $320 for "deluxe" unit from BRS - like this one.

I looked at the UWS+ (same model, but with a second RO) for $271,but would need a booster pump for maximum efficiency ($370 total). I could purchase the Aqua FX 100gpd RO/DI with booster and Auto Flush + new Spectrapure filters for about $350 - and have the auto flush feature (I have hard water, but low PPM).

 

[whyamisofly]

Bump - looking for more opinions, comments, etc.

 

[LefkoNJ]

I have a BRS unit that I added the booster pump and second membrane too. Works great, can make about 35-40 gallons in 4-5 hours. While booster pump is great its all about the pressure coming into the system, which is where the pump helps. I would also highly recommend an inline TDS meter. Best way to know the health of your membranes and filters.

 

[azjohnny]

If you are on a budget go with the refurbished Spectrapure 4 stage for $125, and don't let the refurbished name scare you they are in new condition. I would stay away from Aqua FX

Before you buy a RO/DI do some research on the filters included especially pore size ( smaller the better) The sediment filter serves to protect the membrane

http://spectrapure.com/RO-RODI/RODI-SYSTEMS/Refurbished-90-GPD-RODI-System


here is a link to Spectrapures page on Reef Central, there is a lot of good info
http://reefcentral.com/forums/forumdisplay.php?f=229

 

[whyamisofly]

If you are on a budget go with the refurbished Spectrapure 4 stage for $125, and don't let the refurbished name scare you they are in new condition.
I would stay away from Aqua FX

I am on a "budget" of $350 (would prefer less) - but I also don't want to waste money on replacing filters all the time or losing a lot in waste water.

Why would you stay away from Aqua FX?

 

[whyamisofly]

Up again for the Thursday night crowd.

 

[whyamisofly]

Last ditch effort.

 

[Fish Bowl]

If your budget is 350 basically why not just buy the spectrapure maxcap 180gpd? You'll really appreciate the extra water production speed. Not to mention with any spectrapure unit, the 99% rejection rate will up your DI resin life by a ton IME
If you want to spend less and settle for the 90gpd unit, you're in luck because Marine Depot has it on sale right now too.
http://www.marinedepot.com/SpectraPure_MaxCap_RO_DI_System_w_Manual_Flush_90_to_180_Gallons_Per_Day_RO_DI_Water_Filter_Systems-SpectraPure-SP12291-FIRORDNH-vi.html

 

[azjohnny]

I would only go with Spectrapure or Buckeye Hydro,both are specialized water filtration companies. The link that Fish Bowl provided is a great deal

Unless you have to make hundreds of gallons of water each month I would stay with a 90 gpd membrane. RO/DI filters like to be run for longer periods of time ( I try to make at least 30 gallons at a time, about 1x a week) If you make smaller more frequent amounts you will get TDS creep at the start up and this will cause you to burn through DI faster

I also make 5 gals of drinking water using just the RO section of the filter than using a 3 way valve start using the DI section

here is a link to a 3 way valve
http://spectrapure.com/PARTS-SUPPLIES/VALVES/3-Way-PVC-Ball-Valve-w-1-4in-quick-conect-fittings


your feed water will determine what ratio you should use, if you are below 250 ppm you could try to go 3/1 or 2/1, if you use too low of a ratio you will foul up the membrane prematurely. Spectrapure does sell a UHE RO/DI that can be run at a ratio of 1/1 even in high TDS water but it is $900. My have bad water and my TDS levels are at 650 ppm

One thing to remember water is not that expensive compared to replacing your membrane on a regular basis