RO/DI unit
 

What is different, between the RO/DI systems sold at water purification stores.

and the ones used for reef keeping ?

they both produce H20, with Zero TDS, and PH 7.0 ... so I assume they produce the same thing ? andhence do the same thing?

I believe either is good the only difference I know is that the GPD output seems to be less at most water purification stores. Most I have seen are 25-50 GPD and most reefers like 50+ GPD. Just my .02

so are they the same ?

Ps not asking which one I should buy, just want to know if the units sold for reef keeping do the same as the ones sold by water purificatioon systems ...

The theory is the same, the filters are often different if we are talking about Home Depot type stuff. If you find an RO/DI that has the same sediment filters, carbon blocks, and RO membrane then there really is no difference.

lol jerpa, thanks, but how are the home depot stuff different ? do you know ?

that is the info I am looking for. why is the RO/DI from HD different from the one from BRS lets say. if they both produce the same end product.

They both produce the same end product in theory. Most of the units from HD are meant for drinking water and won't have a DI stage.

Also re the OP. Don't count on RODI having a ph of 7. More often than not it is considerably lower then that. But without any buffering capacity, that number is pretty useless.

Well a low quality sediment filter will allow your low quality carbon block to be exhausted/clogged more quickly. This, and the quality of the carbon block, can impact the RO membrane life if certain chemicals are allowed to make it that far. A low quality RO membrane will have a lower rejection rate exhausting your DI faster. It may also produce more waste per gallon of RO than it should. It could make more than a high rejection membrane because more "dirty" water makes it through. The end result will still be 0 TDS, assuming you maintain the system, but your costs over time will be significantly higher.

To determine the quality of the filters you have to look at the ratings. Not all ratings are equal however. Some rate the actual particle size it filters down to while others use a nominal system that means It filters about 85% of particles that size. With carbon filters you also need to be concerned with chlorine capacity in addition to the pore rating. RO membrane life is greatly impacted by the substances that get to it, chlorine being one of the major concerns. There are several materials that RO membranes are made of and I forget all the differences off the top of my head but this impacts the life of the membrane as well. The rejection rate of the membrane will have a large impact on the DI consumption and most would consider 95+% to be a quality membrane.

What you'll find at the hardware store are drinking water reverse osmosis (RO) systems - not RODI systems.

Compared to good quality RODI systems, drinking water RO systems available at the hardware store typically have:
1. lower quality, and often higher priced prefilters
2. Very low capacity RO membranes (e.g., 12 gpd).
3. no pressure gauge
4. no tds meter
5. compression style fittings
6. no flush valve
7. opaque housings

Russ
The drin

purification stores units dont have DI and they have an extra step(canister) for taste removal(waste of money for reef), DI is required for reef, so its not so recommended for Reef in general.