Best RO/DI unit for <$100?

[reefcapnnick]

Looking for an RO/DI unit under $100. Preferably with some sort of faucet adaptor. 50GPD or more would be nice!

The ebay 6-stage units seem to fit the bill, but I thought I'd check.

[BeanAnimal]

There is no such thing as a "good" RO/DI unit under $100.

Lets start this way... what is your input TDS and how much water a day do you need to make?

[reefcapnnick]

Don't know, and it doesn't matter. Anything above 10gpd would be OK.

[AZDesertRat]

Contact Bryan at www.purelyh2o.com or Walter or Bryan at www.airwaterice.com . Tell them your tap water quality and your needs and they can recommend the best unit for you. Off the shelf $100 ebay units are not the way to go. They will end up costing you much more than a good unit would have to begin with not to mention the frustration.

[reefcapnnick]

AirwaterIce has a Mighty Mite for $99.99 that seems like it would suit me perfectly.

[lewisdw]

I was wondering what kind of problems you've seen/read about with the units you can get via ebay? I purchased one off ebay from filterdirect. It's a 6 stage unit, ~100gpd, and cost around $100. I've been using it for about 2 months now, and it has been great. TDS of my source water is ~180, ~6 after the ro, 0 after the di. I also have a whirlpool ro only unit (3 stage) that I started off with that cost me a lot more (~$180 from homedepot), and it gets the TDS down to about 8.

The filterdirect unit was fully assembled, prompt delivery, and so far, has worked great. Refills aren't that expensive either.

Just wondering.

[reefcapnnick]

Do you remember which eBay seller you got it from?

[pvtschultz]

filterdirect is a great RO/DI source if you ask me. I have been using mine for nearly two years without any problems. They will upgrade from a 100 gpd to a 75 gpd RO membrane which will filter out more of the impurities and prolong the life of the DI resin.

[AZDesertRat]

The FD units have several things that need improving. First is the membrane. They use a 100 GPD that requires 65 psi to operate efficiently. True they will replace it upon request but why should you have to request a change in what they advertise to be a reef ready unit? Seems to me they would take better care of their customers than to sell them a halfa$$ed product.
They also use a cheap hollow tube and call it an efficient DI filter. Look at the AWI Typhoon III or the Purely H2O Optima for example and see what a true DI filter should look like.
You will also find the quality of the filter elements is not on par with the others.
Like I said, by the time you upgrade it to the level of the two I already suggested you will have more invested.
I would also suggest looking at www.buckeyefieldsupply.com 75GPD Premium series and www.thefilterguys.biz Reef Keeper series.
You will soon see that you get what you pay for with RO/DI and it pays to spend just a little more up front to get a better quality unit, better quality water, longer filter life, lower inlet pressure requirements, top notch customer service .........
Call or e-mail any or all of the 4 that I suggested and ask them technical questions then do the same with FD and some of the other ebay units and you will see a huge difference.

An RO TDS of 6 from 180 source water is not very good at all. My tap water is 630 and my RO only is averaging 10 and 11. After DI its 0 for in excess of 250 gallons before I start to see any rise at all.

[pvtschultz]

That is true AZDesertRat, I stood my DI cartridge upright so the water flows from the bottom to top and I don't get the color streaks any more. Their filter is perfectly capable of producing water that is <5ppm TDS which is far from not being reef suitable. I can't justify spending the extra money when my unit with the "crappy" RO membrane and slightly altered DI chamber repeatily produces 0 TDS water. Costs me about $1-$2 a month for DI resin and then the normal filter changes.

[BeanAnimal]

pvt, it's the cots to get to 0 TDS that makes the difference. The higher TDS output of hte cheaper membrane will use DI resin almost 4 times as fast.

Very simple math
200 PPM * 98% = 4 PPM (Dow FILMTEC 75 GPD)
200 PPM * 90% = 20 PPM (GE 100 GPD)

Before anybody starts yapping about the "applied membranes" being the same a "filmtec".. they simply are not. To compare the two membranes, you need to do so under the same operating pressure (about 45 PSI in most homes). Not the 75 PSI that the applied membranes are measured under.

Turning the junk "DI housing" vertical will help a little, but it is still not a properly packed verical housing, nor does it hold the same amount of resin.

I don't know what this becomes such a contested issue. The facts are very simple and spelled out here at least once a week. The people who "spell them out" have nothing to gain, other than tha satisfaction of trying to help people. Instead the arguements start, one side based on fact, the other based on feeling or opinion. It may be because people don't want to admit that they purchased something that is not worth the money they spent on it. It may be because most of the pundents have no idea what they are talking about (other than what they read from the ebay ad, or the sales pitch). It may simply be because some people like to argue for the sake of opposing things that cost money... who knows. However the facts are very simple. Most of the "cheap" units cost more to own and operate. Within reason you get what you pay for.

A simple parallel would be computer printers. The cheaper the printer, the more the renewables cost. Buying a $79 printer is NEVER a good deal. After one year of modest operation the $279 printer will cost LESS than the $79 printer after the same number of pages.

The < $100 RO/DI units are a deal if you only need to make a few gallons of water and/or your input tds is less than 100. IF your input TDS is that low, then your overall resin usage will be minimal. The usage will still be 4 times more than a 98% unit, but with a resin change every year or so, the payoff is way down the road. The same thing with the $79 printer. If you print 2 pages a week, then who cares, your refills will last a lifetime.

Bean