what TDS meter should I get?

[81Shaun]

Thanks AZ . so I checked spectrapures site and they don't have them atleast from what ive seen. I did google it and found out that the filter guys has them so that is probably where ill get it. so it sounds like a better way to go then it is doing a few purposes by installing. where should i install on the line ? closer to the DI or about midways ? thanks man

 

[AZDesertRat]

A DI byass is simply a 1/4" tee and 1/4" ball valve, thats it. If you want to get more elaborate Spectrapure does sell a 3 way valve that gives you a positive shutoff to the DI when flushing but it is a little more expensive than a tee and valve.

All you do is cut the blue line between the RO membrane and the DI canister and insert the tee. Place a couple inches oftubing off the tee and install the valve with some more tubing to reach a sink, drain or bucket or leave it loose so you can draw RO only water for drinking and cooking or to take RO TDS samples from for your handheld meter or all of the above.

 

[Reefing Madness]

Regular old Johny Guest Valve and a T branch, and some tubing.
PPSV011223W / John Guest® 3/8" x 3/8" NPTF Male Valve
Mur-lok RO Tee Union Push Connect - Bulk Reef Supply

 

[81Shaun]

okay so if I buy the 3 way ball valve ill be able to shut the water off completely to the DI? but just buying a T and a ball valve ill still be sending water to the DI and to the drinking water both ? id like to be able to shut the DI off completely when just needing drinking water. I got the aqua pro ap1 TDS today and the unit shut off when im using it? only thing I know is that either the battery are bad or I ordered a bad unit.? also checked tap at around 76-77 degrees and getting like 396-398 TDS out of tap. I also tried using it with my cold water running around 49 degrees and im getting like 400-405 TDS how come ? im going to be using strait cold water into the RO unit which is what you told me to use. anyhow does that mean ill have to heat the RO water coming from the DI ? just a lil bit confused here. anyhow thanks AZ and Reefing Madness.

 

[AZDesertRat]

The water is going to take the path of least resistance so usually the open ball valve if it is pointing down will be that path. The TDS should be the same warm or cold, did you allow the meter time to stabilize between room (air) temperature and water temperature?

You will not have to heat the water for top off, it is such a small amount compared to the total water volume of your system it should affect the overall temperature. When I do large water changes in winter months (not that we have much of a winter in Phoenix) I add a Mag 9.5 pump to my trash can to warm the wate rand mix the salt if it needs warming at all.

 

[81Shaun]

okay first of all what should I be testing out of glass or plastic ? I was using a plastic cup. anyhow I checked out some distilled water should distilled water read zero TDS? well I first of all got 2 TDS from the distilled water and checked it a little later and got 0 so I was like okay ? so next time checked I got like 8 ppm from the distilled water. so i got the TDS EZ and checked out the water and got 8ppm with it so both gauges are reading the distilled water the same. so I got to thinking that if distilled water is not reading 0 then how the heck am I going to be able to know if im getting 0 out of the DI on the RO machine? I did check regular tap in between though and got thinking that maybe some water on the probe might be messing with my results although I did give it a shake so I don't no what im doing wrong. I was asking about warming the water so it would give me accurate results not to top off with. the aqua pro was reading like 398 in 76 to 78 degrees . my understanding is that it should be about the same using cold water but that was not the case using cold water about 50 degrees I got around 405-410 which is a big difference of course. I do believe the gauges are accurate because checking the distilled water both gauges are reading about the the same. this stuff is beginning to be a headache

 

[AZDesertRat]

The TDS EZ is not a temperature compensated TDS meter and is not as acurate as the TDS-3, TDS-4TM or AP-1 so you are probably at the limits of your meters accuracy range. TDS changes with temperature so with a non compensated meter your readings are going to change as the meters probes change temperature between the air and the sample and again when the sample warms or cools. An ATC meter takes care of this behind the scenes so you don't have to do any temperature correction calculations.

 

[Chameleon]

i love the spectrapure stuff but man they kill you in shipping... i always dread filter replacements for this reason

 

[81Shaun]

yeah i no the tds ez is not temperature compensated but just used to see the accuracy of the ap1 i purchased and both are getting the same reading in the tds from distilled water. my ez and the ap1 i read 4 ppm and 8 ppm tds in distilled water but why is that? distilled water isnt it suppoed to have no TDS? I thought 0 ppm should be in the distilled water not sure why I am getting different results using these. I was asking why it is showing a reading for so kinda concerned when i get the ro/di hooked up I will get the right reading which of course should be 0 ppm TDS out of the DI, I am just confused about these meters do I need to be testing out of a glass cup? not sure what the heck is going on

 

[AZDesertRat]

The distilled may not be pure. Many people report good luck with Wal Mart purple cap distilled. I would not trust the AP-1 so use the AP-1 which should be pretty accurate due to its ATC.

 

[81Shaun]

okay thanks az will try and see what happens and will let you no im plan on hooking up my unit as soon as I get some plumbing done to hook into it. anyhow thanks will use the AP-1 I just was curious of what reading the AP-1 and the EZ got in the distilled water and both showed about the same results. anyhow thanks probably going to buy that 3 way valve pretty soon. what size is the line on the spectrapure units? cause I will need to get water tubing and not sure the size of it to hook to the valve. Thanks AZ youve been a huge help with all this stuff your the best with helping ive picked up a good bit of information from you but still alot to learn thanks man

 

[AZDesertRat]

Standard 1/4" tubing size.
Since the distilled water or RO/DI are on the low end of the scale them meters may be close but as the TDS rises as in RO only water, exhausted resin RO/DI or tap water the margin of error will grow dramatically and the readings will be quite different. Also the further the water temerature is away from 77 degrees the further off the EZ will be.

 

[81Shaun]

Hello, thanks ya I am using the AP-1 not going to be using the EZ model but again thanks for the help Az will probably have a bunch more questions to ask ya lol