need advise on ro/di

bellorusha · 03/01/2007, 11:03 AM

i found ro/di unit pretty cheap on ebay and need someone to tell me if this unit is OK and will do the work..

thanks.

http://cgi.ebay.com/Reef-Aquarium-RO...QQcmdZViewItem

OR this unit

http://cgi.ebay.com/New-Reef-6st-100...QQcmdZViewItem

bellorusha · 03/01/2007, 05:01 PM

anybody?

sticky · 03/01/2007, 05:34 PM

Take a look at the filter guys before you buy that stuff. Filter guys have great service and at least 4 people in our reef club have their ocean wave unit. They are a sponsor here.

Fishbulb2 · 03/01/2007, 06:55 PM

top one looks far better than the bottom but I would also recommend using the RC sponsors.

AZDesertRat · 03/01/2007, 06:57 PM

You will do much better using a RC sposnor like www.filterguys.biz , www.buckeyefieldsupply.com or www.purelyh2o.com .
You second choice is probably worth less than they are charging for it and the first one does not give you any brand names on the membrane of filters it contains, thats a big red flag in my book.

xhaust50 · 03/01/2007, 07:29 PM

I had a 6 stage 125G per day unit from the bottom seller, hooked up to a garden hose. Worked really well, TDS usually around 3, never registered any nitrates or phosphates in the tank. It was also much faster than 125G per day, but again it was on a garden hose where the pressure is much greater than interior plumbing (this could also explain the TDS not being 0). Unfortunately I left it outside and the temperature dropped drastically overnight to below freezing. Goodbye RO/DI unit.

AZDesertRat · 03/01/2007, 07:48 PM

The reason the TDS was 3 was exactly my point, it is a substandard unit that does not perform well. Do not try to save money on RO/DI systems, what you save you give up in water quality and life of the components. If it was giving you 3 after DI imagine how bad it was after RO only. My tap TDS is 782 and I get 5.8 from RO only, thats what a quality RO membrane does for you. Thats 99.25% rejection rate with RO only.

xhaust50 · 03/01/2007, 07:59 PM

Quote:

Originally posted by AZDesertRat
The reason the TDS was 3 was exactly my point, it is a substandard unit that does not perform well. Do not try to save money on RO/DI systems, what you save you give up in water quality and life of the components. If it was giving you 3 after DI imagine how bad it was after RO only. My tap TDS is 782 and I get 5.8 from RO only, thats what a quality RO membrane does for you. Thats 99.25% rejection rate with RO only.

I agree with what you are saying. However, again mine was hooked up to a high pressure hose, and if you are overrunning what the system was set up for you will let slight contaminants through. I'd have to estimate that this 125GPH unit was producing atleast 400GPH (4 gallons in 15 minutes). I will buy this unit again, to me it's worth the savings. It's quite likely that the same unit hooked up underneath a faucet will produce 0 TDS as well.

AZDesertRat · 03/01/2007, 09:10 PM

You would have to have been putting over 200 psi through the unit to get a production like that and I seriously doubt you have that kind of pressure. High;y elevated production rates usually indicate a bad membrane and water is bypassing it which I believe was your case thus the 3 TDS after DI, it was trying to make up for a bad membrane.
It will probably never produce 0 TDS in the best of conditions or if it does the DI will be very quickly exhausted due to the poor performance of the membrane.

rsxs1212 · 03/01/2007, 09:18 PM

id get one from filter guys if you dont want to pay much.. but i would invest in a good one.. i fixed up an ebay one identical to your second one.. to get it to about equal with a spectrapure unti (tds meter, 2 psi gauges, dual stage DI) it was 240.. about the price of spectrapure (i got all the extra from filterguys) its still going today with fine DI resin and its been about 7 months. i would just buy a good one from the start

btw in tds is about 190 from tap

ro membranes arent all that good in ebay units.. mainly cause they dont fit housings.. i wrapped some teflon around the black seal part and get about 5-10 tds out of membrane.. usually 10.. ( 5 on a good day

) anyway id rather pay 240 without the hassle and worry

03/01/2007, 11:03 AM	#1
bellorusha Registered Member Join Date: Jun 2006 Location: Brooklyn, NY Posts: 186	need advise on ro/di i found ro/di unit pretty cheap on ebay and need someone to tell me if this unit is OK and will do the work.. thanks. http://cgi.ebay.com/Reef-Aquarium-RO...QQcmdZViewItem OR this unit http://cgi.ebay.com/New-Reef-6st-100...QQcmdZViewItem Last edited by bellorusha; 03/01/2007 at 11:09 AM.

03/01/2007, 06:55 PM	#4
Fishbulb2 Registered Member Join Date: Mar 2006 Location: Bethesda, MD Posts: 1,807	top one looks far better than the bottom but I would also recommend using the RC sponsors. __________________ Just getting back in, but trying to do it right! Current Tank Info: 40 gallon tank. SPS, LPS, few softies

03/01/2007, 09:18 PM	#10
rsxs1212 Registered Member Join Date: Jul 2005 Location: Bradenton Posts: 1,148	id get one from filter guys if you dont want to pay much.. but i would invest in a good one.. i fixed up an ebay one identical to your second one.. to get it to about equal with a spectrapure unti (tds meter, 2 psi gauges, dual stage DI) it was 240.. about the price of spectrapure (i got all the extra from filterguys) its still going today with fine DI resin and its been about 7 months. i would just buy a good one from the start btw in tds is about 190 from tap ro membranes arent all that good in ebay units.. mainly cause they dont fit housings.. i wrapped some teflon around the black seal part and get about 5-10 tds out of membrane.. usually 10.. ( 5 on a good day ) anyway id rather pay 240 without the hassle and worry __________________ 60% of the time it works every time Current Tank Info: 75g RR,asm g3, eheim 1250, 2 1200's one highflow maxistream mod (may do another or med flow.) , 30g sump,fuge, 4x54 T5 lighting SLR reflectors, RO/DI top off, 20L FOWLR, 10 g prop/sps dedicated

03/01/2007, 05:01 PM	#2
bellorusha Registered Member Join Date: Jun 2006 Location: Brooklyn, NY Posts: 186	anybody?

03/01/2007, 05:34 PM	#3
sticky Registered Member Join Date: Feb 2003 Location: Wausau, WI Posts: 704	Take a look at the filter guys before you buy that stuff. Filter guys have great service and at least 4 people in our reef club have their ocean wave unit. They are a sponsor here.

03/01/2007, 06:57 PM	#5
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	You will do much better using a RC sposnor like www.filterguys.biz , www.buckeyefieldsupply.com or www.purelyh2o.com . You second choice is probably worth less than they are charging for it and the first one does not give you any brand names on the membrane of filters it contains, thats a big red flag in my book.

03/01/2007, 07:29 PM	#6
xhaust50 Registered Member Join Date: Jul 2006 Location: Smithtown, NY Posts: 301	I had a 6 stage 125G per day unit from the bottom seller, hooked up to a garden hose. Worked really well, TDS usually around 3, never registered any nitrates or phosphates in the tank. It was also much faster than 125G per day, but again it was on a garden hose where the pressure is much greater than interior plumbing (this could also explain the TDS not being 0). Unfortunately I left it outside and the temperature dropped drastically overnight to below freezing. Goodbye RO/DI unit.

03/01/2007, 07:48 PM	#7
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	The reason the TDS was 3 was exactly my point, it is a substandard unit that does not perform well. Do not try to save money on RO/DI systems, what you save you give up in water quality and life of the components. If it was giving you 3 after DI imagine how bad it was after RO only. My tap TDS is 782 and I get 5.8 from RO only, thats what a quality RO membrane does for you. Thats 99.25% rejection rate with RO only.

03/01/2007, 09:10 PM	#9
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	You would have to have been putting over 200 psi through the unit to get a production like that and I seriously doubt you have that kind of pressure. High;y elevated production rates usually indicate a bad membrane and water is bypassing it which I believe was your case thus the 3 TDS after DI, it was trying to make up for a bad membrane. It will probably never produce 0 TDS in the best of conditions or if it does the DI will be very quickly exhausted due to the poor performance of the membrane.