rodi unit

[PiscesGirl2]

Anyone know anything about the WaterGeneral rd-102?

Just wondered if it was a good unit.

[UnderCoverDork]

i have seen them on ebay. i have not heard to much about them. I would recommend the typhoon III

[chemesgh]

I've had a WaterGeneral RD-106 up and running for several weeks now. I decided to go with it after reading some good reviews about it, and the price was right. I've been using it for top off and water changes, but haven't put a TDS meter on it yet. Hopefully I can find one this weekend here in town.

[PiscesGirl2]

hmm mine is a 102.
Don't know what the difference is...what did you pay for it?

[chemesgh]

I believe it was $140 shipped off of E-bay. I think the only difference is the 106 comes with a 4 gallon -ish pressure tank that lets you have 4 gallons on hand at all times ready to use. I think it was originally designed for the drinking fauct it comes with, but it works great for topping the tank off! Otherwise I typically get 3-4 gal/hr at the "trickle rate."

[PiscesGirl2]

thanks

[AZDesertRat]

You can do much better here on RC. The unit you are looking at is fine for drinking water but leaves a lot to be desired for reef use. The quality of the filters and the components is lacking and water quality and DI life is just not the same as a unit that is designed for reef use.
Look at vendors like
www.thefilterguys.biz
www.buckeyefieldsupply.com
www.melevsreef.com
www.spectrapure.com
www.purelyh2o.com

Look for things like standard size 10" vertical refillable DI cansiters and cartridges, pressure gauges, autoshutoff valves and good carbon filters like 0.5 to 1.0 micron Chlorine Guzzler types. Also look for low micron rated prefilters, an absolute rated filter is you can get it instead of a nominal rated one and a 75 GPD RO membrane not a 100 or falsely labelled 110 or 125 GPD ones.
Very good units are in the $150 range with better units with TDS meters and other additions for about $200. Any less and you are giving something up, usually its water quality and component life.

[scotmc]

I was in the same boat a week ago. I also saw the water general on Ebay. I talked the jim at the filter guys. It is well worth the exrta money. With shipping, it was under 100 more. Pay now or pay latter.

[chemesgh]

Just curious, do you have any data on side by side comparisons of the different units? I'd like to see benchmarks on how the units compare based on initial cost vs. cost to replace components vs. differences in water output quality. What's the difference between fine for drinking and "reef quality?" I'm not asking to be a pain, I'd sincerely like to know what the differences are vs. costs as there is some point where water quality vs. cost of the unit converge. If I can get 90% of the filtration value for half the cost, my water will just have to be a little less pure.

[AZDesertRat]

I have my own personal data. I keep logbooks on every gallon of RO/DI water I produce. From my experience I can tell you what kills you is DI resin life if you make much water at all. What happens is lesser quality prefilters and carbons due a poor job of protecting the RO membrane from both particulates and chlorine thus shortening the life of the membrane and causing it to work harder ending up with lower quality RO product water. Higher RO TDS shortens the life of the DI dramatically. A very accurate rule of thumb tells us for every 2% you increase the efficiency of the RO membrane you effectively DOUBLE the life of the DI resin.
In my own case, I used a modified drinking water unit for about 10 years. It started out as a Watts Premier unit from Costco but being as I live almost across the street from Premier, I carried the new unit in still in the box and they swapped out the 25 GPD membrane for a 75 GPD membrane for $35. I added a vertical refillable DI and always used high quality fresh sealed DI resin from trusted sources and averaged 150 gallons per DI refill before I started to see a RO/DI TDS of 2-3 when I refilled the cartridge. My tap water TDS is 750-850 and I do have a water softener. After RO I was seeing a TDS of 13-15 which is pretty good.
I now own a reef quality RO/DI unit. (Spectrapure MaxCap). The tap water TDS is still the same but I now average a RO only TDS of 6.2 to 6.4 max. My DI now lasts in excess of 630 gallons per cartridge and thas changing it out when I first see a reading over 1.0 instead of 2-3. Recently Randy Holmes Farley posted his Spectrapure membrane lasted between 9 and 10 years before switching it out. I can say with confidence that is a direct result of using high quality replacement filters and maintaining the system as directed. My old membranes lasted 15 to 24 months using Premiers replacements and not much longer using slightly better filters. With the MaxCap and using their replacements I fully expect to see 5+ years at the very minimum before I need to replace the membrane and hopefully 8 to 10 years.
As I said I keep log books of every gallon showing TDS at tap, post carbon/pre RO, RO only, post MaxCap and final effluent. I also monitor incoming pressure and RO pressure, temperature and total gallonage so I have pretty good records. Time will tell.
I know Spectrapure has some spreadsheets showing operating costs of various units on the market but I don't know if they are available online or not.

[chemesgh]

Originally posted by AZDesertRat
I have my own personal data. I keep logbooks on every gallon of RO/DI water I produce. From my experience I can tell you what kills you is DI resin life if you make much water at all. What happens is lesser quality prefilters and carbons due a poor job of protecting the RO membrane from both particulates and chlorine thus shortening the life of the membrane and causing it to work harder ending up with lower quality RO product water. Higher RO TDS shortens the life of the DI dramatically. A very accurate rule of thumb tells us for every 2% you increase the efficiency of the RO membrane you effectively DOUBLE the life of the DI resin.
In my own case, I used a modified drinking water unit for about 10 years. It started out as a Watts Premier unit from Costco but being as I live almost across the street from Premier, I carried the new unit in still in the box and they swapped out the 25 GPD membrane for a 75 GPD membrane for $35. I added a vertical refillable DI and always used high quality fresh sealed DI resin from trusted sources and averaged 150 gallons per DI refill before I started to see a RO/DI TDS of 2-3 when I refilled the cartridge. My tap water TDS is 750-850 and I do have a water softener. After RO I was seeing a TDS of 13-15 which is pretty good.
I now own a reef quality RO/DI unit. (Spectrapure MaxCap). The tap water TDS is still the same but I now average a RO only TDS of 6.2 to 6.4 max. My DI now lasts in excess of 630 gallons per cartridge and thas changing it out when I first see a reading over 1.0 instead of 2-3. Recently Randy Holmes Farley posted his Spectrapure membrane lasted between 9 and 10 years before switching it out. I can say with confidence that is a direct result of using high quality replacement filters and maintaining the system as directed. My old membranes lasted 15 to 24 months using Premiers replacements and not much longer using slightly better filters. With the MaxCap and using their replacements I fully expect to see 5+ years at the very minimum before I need to replace the membrane and hopefully 8 to 10 years.
As I said I keep log books of every gallon showing TDS at tap, post carbon/pre RO, RO only, post MaxCap and final effluent. I also monitor incoming pressure and RO pressure, temperature and total gallonage so I have pretty good records. Time will tell.
I know Spectrapure has some spreadsheets showing operating costs of various units on the market but I don't know if they are available online or not.

After looking back at my post, it seemed I might have come across a bit sarcastic, which I did not mean to be. I'm not questioning your knowledge on these systems, I just sincerely would like to see different systems benchmarked off of the same water source to see what the differences are, as well as purchase and maintenance costs for each. A matrix with all of this info would be awesome!

I'm definitely not trying to defend the unit I bought, as I would simply make it into a kitchen water supply and get another unit for the tank if I saw hard data supporting the justification for it.

Also, I've never looked at it, but wouldn't it also be possible to buy something more economical with not so great components, and then switch these parts with more well known quality parts? basically just changing them out at the tubing fittings? It's fairly easy to find tubing, ferrules and PE nuts and adapters at Lowes/HD. Or you could order from mcMaster if you needed to.

You definitely are dedicated to your systems which is highly admirable, it would probably benefit all of us to possess some of that type of commitment!

[sage_commander]

I'm threadjacking again...

AZ, you posted a link to a page a while back with a handheld TDS meter. Could you post that again? I ordered the Ocean wave + from the filter guys but got it without the TDS meter. I figured I would try to get one for Christmas or my birthday. Thanks!

[AZDesertRat]

I learned from upgrading the Premier unit over time I had much more invested in the end. If thats the way someone needs to go I would suggest they get the very best RO only unit they can afford at the time and add the DI, autoshutoff, possibly drinking water kit and such later. When you get the less expensive RO/DI systems you sacrifice things like full sized filters and housings for one. Its more expensive to buy the non standard sized replacement filters and your sources are more limited. You also get much shorten filter life and sometimes even get a non standard membrane and housing that will not hold a standard 1812-75 Dow membrane.
When you buy a full sized RO only you can add a good vertical DI kit for about $38, a pressure gauge for $12 to $18, an autoshutoff for $6 to $12 etc. It all adds up and you soon exceed the cost of the good RO/DI to begin with. I know sometimes its hard but its better to continue buying bottled water and save a few more $$$ than to make a snap purchase. Back in 1996 there were not nearly as many choices but today there are lots of good vendors selling high quality individually hand assembled reef quality units, you don't have to settle for a drinking water system that will never produce the quality of water you come to expect.

[AZDesertRat]

The best handheld TDS meter is the HM Digital COM-100 by far. I believe several if not all of the sponsors I mentioned earlier carry them. They are a fantastic instrument. I did some comparison testing with it against a benchtop lab quality Thornton conductivity meter and was very pleasantly surprised.

[Nanz]

Originally posted by AZDesertRat
I have my own personal data. I keep logbooks on every gallon of RO/DI water I produce. From my experience I can tell you what kills you is DI resin life if you make much water at all. What happens is lesser quality prefilters and carbons due a poor job of protecting the RO membrane from both particulates and chlorine thus shortening the life of the membrane and causing it to work harder ending up with lower quality RO product water. Higher RO TDS shortens the life of the DI dramatically. A very accurate rule of thumb tells us for every 2% you increase the efficiency of the RO membrane you effectively DOUBLE the life of the DI resin.
In my own case, I used a modified drinking water unit for about 10 years. It started out as a Watts Premier unit from Costco but being as I live almost across the street from Premier, I carried the new unit in still in the box and they swapped out the 25 GPD membrane for a 75 GPD membrane for $35. I added a vertical refillable DI and always used high quality fresh sealed DI resin from trusted sources and averaged 150 gallons per DI refill before I started to see a RO/DI TDS of 2-3 when I refilled the cartridge. My tap water TDS is 750-850 and I do have a water softener. After RO I was seeing a TDS of 13-15 which is pretty good.
I now own a reef quality RO/DI unit. (Spectrapure MaxCap). The tap water TDS is still the same but I now average a RO only TDS of 6.2 to 6.4 max. My DI now lasts in excess of 630 gallons per cartridge and thas changing it out when I first see a reading over 1.0 instead of 2-3. Recently Randy Holmes Farley posted his Spectrapure membrane lasted between 9 and 10 years before switching it out. I can say with confidence that is a direct result of using high quality replacement filters and maintaining the system as directed. My old membranes lasted 15 to 24 months using Premiers replacements and not much longer using slightly better filters. With the MaxCap and using their replacements I fully expect to see 5+ years at the very minimum before I need to replace the membrane and hopefully 8 to 10 years.
As I said I keep log books of every gallon showing TDS at tap, post carbon/pre RO, RO only, post MaxCap and final effluent. I also monitor incoming pressure and RO pressure, temperature and total gallonage so I have pretty good records. Time will tell.
I know Spectrapure has some spreadsheets showing operating costs of various units on the market but I don't know if they are available online or not.

How important is the DI stage? I have a 4 stage RO unit called TapMaster and it has served as a great source of water for my Discus.