my used spectrapure unit

[Tom@HaslettMI]

Hi AZ,

I just picked up a used RODI unit. The tag is a bit tore up and I'm hoping you'll be able to tell me/confirm the model# and possibly provide any other pertinent info.

Thanks,
Tom

[MizTanks]

Look up the model # under Spectra pure.

[Tom@HaslettMI]

Look up the model # under Spectra pure.

That's my plan, however, the first letter of the model# is partly scratched off. It looks like either an "MPDI" (which would match a currently produced model) or BPDI (which could be a model made back in 2000). Just to add to the confusion the person I got it from said it was an EPDI (though he got it used and was simply reselling it).

AZ really knows his stuff and is a big proponent of SpectraPure, so I figured I'd get his insight.

Tom

[MizTanks]

That's my plan, however, the first letter of the model# is partly scratched off. It looks like either an "MPDI" (which would match a currently produced model) or BPDI (which could be a model made back in 2000). Just to add to the confusion the person I got it from said it was an EPDI (though he got it used and was simply reselling it).

AZ really knows his stuff and is a big proponent of SpectraPure, so I figured I'd get his insight.

Tom

It's an M~I can see it, trust me

[AZDesertRat]

I would agree, its probably an MPDI, 60 GPD.
If you are looking for replacement filters get the FILTKIT-3PK-CSPDI on sale here for $43 for the set. If you want to replace the membrane get the 90 GPD MEM-090 on sale for $30 and a matched flow restrictor for another $5.
http://www.spectrapure.com/email/cus...reciation.html

If you don't have a TDS meter you will want one to tell the condition of your RO membrane and DI resin, the TDS-4TM found here for $29.95 is a good choice and gives you a digital thermometer too.
http://www.spectrapure.com/St_quality_p5.htm

[Tom@HaslettMI]

Thank you AZ. That is the info I was looking for.

I was thinking of picking up this TDS meter. I like the idea of having dual inline monitoring. Do you have any insight on whether this is a good company/product?

Thanks,
Tom

[AZDesertRat]

You didn't post a link but I assume its the HM Digital DM-1 dual inline.
I have a couple of them but much prefer a good handheld for several reasons. One is the inlines are not really temperature compensated so can be off unless your air temperature and water temperature are not exactly the same which never happens. Another is they cannot be used portable so are dedicated to two points, usually post RO and post DI so you cannot test tap water, ATO container water, the LFS water, bottled water, loan it to your buddy etc. I like to know what my tap is as well as the RO only so I can calculate my rejection rate then check my DI TDS and also the water in my top off container so the handheld is much more convienient and more accurate, especially on the low end like RO and RO/DI.

[Tom@HaslettMI]

You make a very compelling argument for a portable meter. Your input is much appreciated.

A couple more questions...

1. Where should I install a pressure gauge? There was a loose one included. I'm guessing between the tap and the unit.
   
2. Should I just replace the membrane or is it worth hooking it up and seeing what shape it is in?

FYI - the blue word "this" in my post is the link. The brand is Senno or something like that.

Thanks for all of your help,
Tom

[AZDesertRat]

The pressure gauge should go after the carbon block and before the membrane, this tells you the pressure available to the membrane.
If the membrane has remained wetted and the original owner kept up with the regular replacements and disinfections it may be in good shape. The TDS meter will tell the story. Once it has been running a half hour or so get a tap water and a RO only TDS reading and calculate your rejection rate (Tap TDS - RO only TDS divided by the tap TDS x 100 will give you that. An example would be say your tap TDS is 250 and your RO only TDS is 5, 250-5=245, 245/250=.98, .98x100= 98% rejection which is where you want to be. New Spectrapure membranes are better than 98% rejection, my current one is still 99.35% after 2.5 years.
You want to stay in the 98% range or better because for every 2% it drops it cuts your DI resin life in half and the cost of ownership goes up significantly.

A.J.

[Tom@HaslettMI]

Thanks for all of your help.

The RO unit also came with this piece.

Is this a restrictor, check valve, or something else altogether?

Speaking of check valves do I need one?

And lastly (for now) do you know the SpectraPure replacement part # for the threaded hose connection nut-thingy (such as would be used on the above picture). There appear to be two 0.25 inch options and I'm not sure of the difference.

Thanks,
Tom