Which RO/DI Unit should I get?

[frank10]

<a href=showthread.php?s=&postid=6670987#post6670987 target=_blank>Originally posted</a> by szwab
yes you just need to get another canister and DI cartridge. Hook it up to the output of the RO. then the output of the DI becomes the output of the whole unit. you can do this for about 40 bucks or less and Viola you have converted to RO/DI.

Any suggestions on a canister and DI cartridge?

 

[narcist21]

That unit doesn't have DI which is critical because the R/O and sediment filters will leave you with detectable solids after the process. Also, when you look you should get a 75gpd unit as the membranes have a higher rejection value.

 

[69camaro540]

check out filter direct. they are on ebay all the time. i got a 6 stage ro/di with storage tank for a little over $100. it works very good. check out there website www.filterdirect.com or they may be under water general.

 

[dtaranath]

<a href=showthread.php?s=&postid=6671440#post6671440 target=_blank>Originally posted</a> by 311Style
Dont mean to ninja a thread but what do you guys think about this RO/DI

http://cgi.ebay.com/AQUA-SAFE-100GP...437211872QQcategoryZ20684QQrdZ1QQcmdZViewItem

Only reason I ask is because im working on this reef on a students budget and im trying to get a new skimmer/sump going.. But I figure this is most important at this point.

Like narcist said, that's only RO. You're going to have to shell out for a DI.

The bottom line is, the Typhoon III is the best value, considering all the extras you get with it.

 

[szwab]

<a href=showthread.php?s=&postid=6671479#post6671479 target=_blank>Originally posted</a> by frank10
Any suggestions on a canister and DI cartridge?

check out buckeyefieldsupply.com they should have all the parts.

 

[Absint Reefer]

How much is the Typhoon III?

 

[JimR]

$200

 

[frank10]

<a href=showthread.php?s=&postid=6672758#post6672758 target=_blank>Originally posted</a> by szwab
check out buckeyefieldsupply.com they should have all the parts.

i'll try them out

 

[szwab]

russ is a good guy and good prices to boot

 

[shag26272]

the reason I asked about the membranes is because it was stated that the "EBAY" units dont use the quality membranes and such, I really dont understand why someone would say that when my aquasafe unit from EBAY has the exact same 75GPD DOW Filmtec membrane.

 

[AZDesertRat]

Aquasafe does not use Dow Filmtec membranes. They have been using Applied Membranes which are constructed from Dow material but not the same thing. Applied takes 65 psi to produce water vs Dow Filmtec at 50 psi.
They also use a hollow horizontal tube and call it a DI filter which is not as efficient as a true vertical 10" canister design. In addition they use a poor combination of prefilters and carbons including GAC.
Again they do not compare.

 

[shag26272]

http://www.appliedmembranes.com/residential_tapwater.htm

this is what is in my aquasafe unit, it says 50 psi and greater than 98% rejection. I still dont understand.

 

[AZDesertRat]

Unless you specifically requested that membrane that is not what you have. That is not what they supply normally.
Look here at the first group that comes up:

http://www.appliedmembranes.com/Product_Catalog/Membranes.pdf

That is what they come with and they show 65 psi for your membrane.
Its just another way vendors deceive you.

 

[shag26272]

yeah maybe so I cant remember now, whats the price difference between the two?

 

[AZDesertRat]

I have never priced the Applied but the 75 GPD Dow Filmtec can be had for $42 to $45 at several places including AWI and Buckeye.

 

[shag26272]

do you think it would be wise for me to switch it to the dow?

 

[AZDesertRat]

If you are not having problems with what you have I wouldn't change it until it is worn out. If you are experiencing things like high RO only TDS, short DI life, slow production, high pressure drop across the membrane or similar signs then it might be a good idea. Applied is not a bad membrane they just require higher pressures to produce water and might possibly be 1 to 2% less efficient. Not nearly as bad as Dows 100 GPD at only 90% rejection (which is a nanofilter by the way and not a true RO)which is another way some vendors cut costs.
The only way to tell is with a TDS meter, pressure gauge and timing flows to see what it is actually producing. Thats one of the big reasons I recommend the Typhoon III as it comes with a TDS meter and pressure gauge to help you keep track of you units performance.

 

[frank10]

check it with a TDS meter

 

[shag26272]

mine came with TDS and pressure gauge, I havent hooked up the pressure gauge yet but it seems to flow pretty well, I have only put a few gallons through it so far, and at first it tested at around 20 and now its down below 5, maybe about 10 gallons total trhough it so far being I only have a 6 gallon tank, I was told the TDS would eventually drop to near 0 though

 

[AZDesertRat]

Keep track of the raw water TDS, RO only TDS and RO/DI TDS all three. Thats the only way you can judge the performance of the unit. The RO only should be 98 to 99% less than the untreated water when the membrane is new. DI should be 0 or very near.