Dual TDS Meters

igadget56 · 07/09/2011, 06:41 PM

I have been checking out RO/DI systems.Why would you want
dual TDS meters?

Defuse · 07/09/2011, 06:46 PM

It is so you can see Input/Output values throughout the filtration process.

I have two TDS meters that both have In/Out switches so I can see what my tap water is and what I am at after the first stage. Also I can see pre stage 5 and final product values.

According to the SpectraPure documentation I am supposed to use the TDS meters as both informational and as a guide as to when it is time to replace filters and what filters.

Eric the half-bee · 07/09/2011, 08:50 PM

Redundancy is good in many applications.

stingythingy45 · 07/09/2011, 09:00 PM

So you can tell thet the TDS before the DI resin is high and will most likely exhaust the di resin.One tds before resin.....one after.

jeff@zina.com · 07/10/2011, 07:02 AM

The first goes after the membrane, before the DI, the second on the output of the DI. If the first reads low and the second is rising, then the DI needs to be changed. If the first is rising, the membrane needs to be changed.

It's also helpful to occasionally test the source so you can calculate the rejection rate of the membrane.

And before you ask, a pressure gauge will be helpful to tell you when the sediment filter is clogging.

Jeff

07/09/2011, 06:41 PM	#1
igadget56 Registered Member Join Date: Jun 2011 Posts: 820	Dual TDS Meters I have been checking out RO/DI systems.Why would you want dual TDS meters?

07/09/2011, 08:50 PM	#3
Eric the half-bee Passer of gasses Join Date: Oct 2007 Location: Space Coast, FL Posts: 837	Redundancy is good in many applications. __________________ MOLON LABE - King Leonidas I A government big enough to give you everything you want is big enough to take everything you have. – Barry Goldwater Current Tank Info: Semi agressive reef-400 gal.-8 tangs,2 rabbit fish,zebra moray,blue ribbon eel,Janss' pipe,pair bangaiis,wrasse,tomato clown,maroon clown

07/09/2011, 09:00 PM	#4
stingythingy45 Registered Member Join Date: Aug 2007 Location: MA Posts: 3,296	So you can tell thet the TDS before the DI resin is high and will most likely exhaust the di resin.One tds before resin.....one after. __________________ Bob Current Tank Info: 90 gallon,mixed Reef,2-250 watt Optix 3 pendants(Phoenix 14K)2-54 watt T5 Super actnics ,ASM G-2 Gate/recirc mods,70 gal. basement sump,20L ref

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07/09/2011, 06:46 PM	#2
Defuse Registered Member Join Date: Jun 2011 Location: Memphis, TN Posts: 207	It is so you can see Input/Output values throughout the filtration process. I have two TDS meters that both have In/Out switches so I can see what my tap water is and what I am at after the first stage. Also I can see pre stage 5 and final product values. According to the SpectraPure documentation I am supposed to use the TDS meters as both informational and as a guide as to when it is time to replace filters and what filters.

07/10/2011, 07:02 AM	#5
jeff@zina.com Registered Member Join Date: Apr 2010 Location: Naples, FL Posts: 3,345	The first goes after the membrane, before the DI, the second on the output of the DI. If the first reads low and the second is rising, then the DI needs to be changed. If the first is rising, the membrane needs to be changed. It's also helpful to occasionally test the source so you can calculate the rejection rate of the membrane. And before you ask, a pressure gauge will be helpful to tell you when the sediment filter is clogging. Jeff