TDS Meter

[Mules1]

I have the BRS 5 stage ro/di. The TDS meter is plumbed in after the fourth stage and before the 5th. It usually reads 5ppm in and 0ppm out. My question is: Is there a problem with relocating the "in" to the raw water side so I can get a true reading of incomming TDS or "don't worry about it 'cause the TDS 0 comming out is all that's important!"

[Buckeye Hydro]

In a perfect world, you'd want to test/monitor TDS in 3+ locations:
1. Tap water
2. RO water
3. After the DI stage(s)

If you have an inline meter with just two probes, and you have to choose which of the 3 location you want to monitor, the best choice is the RO water and the DI water (Nos. 2 & 3 above).

Another option is to get another inline meter with a single probe - like the SM-1.
http://i224.photobucket.com/albums/dd293/BuckeyeFS/sm1337.jpg

or get a handheld TDS meter to check your tap water.

Russ

[Mules1]

Thank you very much for your reply. I think the way I'm going to go is a handheld - then I can check my tap and doublecheck my ro/di.

Thanks again.

[Signal151]

I have the BRS 5 stage ro/di. The TDS meter is plumbed in after the fourth stage and before the 5th. It usually reads 5ppm in and 0ppm out. My question is: Is there a problem with relocating the "in" to the raw water side so I can get a true reading of incomming TDS or "don't worry about it 'cause the TDS 0 comming out is all that's important!"

I have the same equipment (BRS 5 stage) and I did just that. I relocated the first probe to test the unfiltered tap water going in to the system. Every month or so I relocate the probe back to after the RO unit to check on the status of the first four stages. This method has not caused any problems in the eight months I've owned the system.

[Buckeye Hydro]

Be careful tho if you are repeatedly removing the probes from the quick connect tees. If you do that alot they will start leaking.

Russ

[disc1]

Knowing the incoming tap number is only important if you think you have a bad membrane. Otherwise who cares? The reason for measuring either side of the di resin is to how well the di is performing and determine when it needs to be changed. So in that sense you're better off taking that reading between the membrane and the di. What will you possibly learn by measuring the incoming tap number? What use would it be on a regular basis?

[Buckeye Hydro]

Knowing the feedwater TDS (which typically isn't static) allows you to calculate the rejection rate - that is, it allows you to know how the membrane is working.

[disc1]

Knowing the feedwater TDS (which typically isn't static) allows you to calculate the rejection rate - that is, it allows you to know how the membrane is working.

But for that you would need to have one before the membrane and one after but before the DI. So you would need three meters, and that would surely be better than two. But if you only have two, which is the more important to know on a daily basis? Which typically wears out faster, RO membrane or DI resin?

[Buckeye Hydro]

In a perfect world, you'd want to test/monitor TDS in 3+ locations:
1. Tap water
2. RO water
3. After the DI stage(s)

If you have an inline meter with just two probes, and you have to choose which of the 3 location you want to monitor, the best choice is the RO water and the DI water (Nos. 2 & 3 above).