Best RODI

york1

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I am getting back into reef tanks after a 20+ year hiatus.It is mind blowing how much has changed. I am looking to get an RODI system for my 29gal biocube. I am trying to keep this tank on somewhat of a budget. With so many options what would you recommend for an RODI system given the small tank size?
 
ARC may have a Seachem 100gpd - 4 stage available for sale. I believe were asking $150 for it with all new filters.
 
SpectraPure, Triton, and Air/Water/Ice are all great RODI Units
 
There's nothing really special about the different manufacturers. Most any of the good ones all come with Dow R/O membranes. Then it's decent sediment and carbon filters with or without a DI canister.

It really comes down to the quality of the canisters that hold the filters. You run into problems when you go really cheap. This is where you'll see seals blow out or cracked housings.

The Seachem one we have is in good shape with all new filters. It's easily upgrade-able down the road if you want to add stages or TDS meters. Yes, we're asking $150 but make us a reasonable offer and you can have it in your hands tomorrow.
 
atticusfit;1112977 wrote: i went with the BRS 75gpd 6 stage caught it on sale and has never let my down.

+1

I have the 7 stage 150gpd, had it 1 1/2 years now. still get 0tds out of it before DI unit. I change the sediment filter every 6 months and carbon block once a year, I have never seen my DI resin deplete
 
bought mine back in the day from buckeye field supply (different name now) and its still working just fine
 
Thanks for all the info. Now I just need to see how much $ my wife will let me spend
 
York1;1113020 wrote: Thanks for all the info. Now I just need to see how much $ my wife will let me spend

tell her it also makes drinking water so no more lead water like in Flint
 
Based on experiance and after using a LOT of different units here is what Ive come up with

Any brand is fine. All the housings and frames are pretty much the same. I would however opt for a plastic frame over a metal one(they rust), and clear filter housings(so you can see when they need to be changed).

Anything over a 4 stage Ro with a DI section is overkill. We have great water here in Atlanta, dont waste your money. My unit is a 5 micron sediment filter, 1 micron carbon, RO, DI. Thats it and I rarely need to change the DI resin.

If you have an extra sediment or carbon filter, no biggie. Just costs more to change filters.

For the membrane, the 75 GPD are the most efficient in RO vs waste produced. 100 GPD are also good if you get the right brand(which is Filmtec).

For sediment and carbon filters, just whatever is the right micron and cheap.

DI resin, I like the color change resins so you can see it being used up. Its also recommened to get sealed canisters as they wont go "bad" when in contact with moist air. I just get the bags and seal them tight when Im not using them. Seems to work ok for me and its cheaper.

I would also spring for a float valve and shut off, as well as a dual stage TDS meter(one on input one out RO output) I actually have a 3 stage so I can see after the DI as well. This will tell you when you need to replace the membrane.

For money, I have not seen a setup like mine go for more than around $200.

So to wrap up. 5 stage max, $250 max. Brand doesnt matter, only filters do.
 
There are also a few more option to consider as well on the unit: pressure gauge built in, plus water saving feature (2membranes upgrade kit), 3 way diverter to make that di resin last longer, the membrane flush valve, that extra tds meter after every stage to make sure when u need to switch/replace filters, maybe an extra booster pump for the pressure... There is a lot of things u can do to it. U can always buy a standard unit and upgrade it to your liking with those add on. Mine are not the best one but u r more than welcome to come by and look at it before buying one.
 
Good advice all around - especially from Anit77 and EnderG.

The manifold is pretty standard. Clear canister on at least the sediment housing is nice because you can SEE when it gets funky.

You can get sediment cartridges for $3 (ask me where...) - keep that and the carbon block changed often and it prolongs the life of the membrane. Dow/Filmtec membranes are the best, but there's less than 1% rejection rate between it and say, a CSM membrane which is considerably less expensive. Colour-changing DI is nice (with a clear housing) because you can see when it's exhausted.

I also like to have an HM Digital DM-1 inline TDS meter on any unit. I personally configure it to test TDS on unfiltered water and filtered water. Some put it before and after the DI, whatever floats your boat. With that, regardless of what kind of system you have, you can push a button and find out what your TDS is and that is an indication of whether your cartridges need to be changed.

The trick with RO and RO/DI is water pressure. All membranes except low pressure (LP) membranes are designed to work best with 65 PSI across the membrane with water at 77 F. You can't always control the temperature of the water (do NOT run warm or hot water through a membrane). Pressure is something that can be adjusted and if you have low pressure a booster pump is a worthwhile investment.

If your pressure is low, your ASV (auto shutoff valve) may not work properly and if it takes longer than it should to filter water, you will waste more than the 3 or 4 gallons of brine (wastewater) to 1 gallon of permeate (filtered water). You can also get a permeate pump which is non-electric but recirculates the water through the membrane, to boost pressure.

If you have any further RO questions, PM me for more info if you wish.

Oh and anything more than a 4-stage system is a waste, IMO. You need sediment, carbon, membrane, DI. If you're using it for drinking water too you might want an inline carbon post filter too, but that's about it.

Jenn
 
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