RO water TDS

[jc061471]

I have an RO only water filtration system and this is the TDS reading I currently get. This is the water I use for my 120 gallon FOWLR tank (top offs and water changes). My tank just completed its cycle 2 days ago but I haven't stocked the tank yet. Is this a safe and acceptable level?

 

[Tanthaitrung]

Your TDS tester must be calibrated (you can buy calibration solution).

The TDS must be zero before top off or water change. You need to add DI stage to your RO system to absorb TDS.

 

[BeachVacationer]

You buy a gallon of distilled water and test that. It should read zero. If your RO filter is brand new, let it make more RO water and see if the TDS goes down. I have just a RO unit and it's TDS is 2. Else you need to replace your cartridges. What's your TDS of your tap water?

 

[fishchef]

Actually you should calibrate it with calibration fluid. Basically, if the TDS from your membrane is 10 percent of your tap TDS your membrane needs to be changed. Its better if you have a DI.

 

[xREEFINaintEZx]

I'd get the calibration fluid. I use this for my membranes.https://www.premierh2o.com/pages/tds-calculator

 

[jc061471]

Thanks everybody for all the feedback. I tested again but this time I waited for the numbers to stabilize on my meter before getting a value. Tap reads 492 and RO 27. Based on the values (27 is 5.5% of 492 and filtration system is operating at 94.5% efficiency) my filter is ok right? It's kind of early to change the filters since its only like 7 months old. But come to think of it looking at the instruction manual for my meter the manufacturer claims it has already been professionally calibrated and no further calibration is necessary. I think I'll buy some distilled water when I get the chance and manually recalibrate to make sure. Or better yet the calibration fluid. Where can I get that?

 

[mcgyvr]

Your meter and membrane are probably fine..

In this world we all use an additional stage (DI) to remove the rest of the TDS that the RO membrane cannot..
You don't have one so you can either add a DI stage to your current filter, buy a higher rejection rate RO membrane or just use the water as is and hope that TDS doesn't cause a problem..

No one can tell you whats in the remaining 34 ppm... It could be totally fine.. Could be trouble..

 

[Tanthaitrung]

Thanks everybody for all the feedback. I tested again but this time I waited for the numbers to stabilize on my meter before getting a value. Tap reads 492 and RO 27. Based on the values (27 is 5.5% of 492 and filtration system is operating at 94.5% efficiency) my filter is ok right? It's kind of early to change the filters since its only like 7 months old. But come to think of it looking at the instruction manual for my meter the manufacturer claims it has already been professionally calibrated and no further calibration is necessary. I think I'll buy some distilled water when I get the chance and manually recalibrate to make sure. Or better yet the calibration fluid. Where can I get that?

Distilled water just for checking if your TDS tester is reading correctly. To calibrate, you need calibration solution.

 

[Tanthaitrung]

Dear all,

Anyone using this TDS tester? All good reviews, no need to calibrate.

http://www.marinedepot.com/HM_Digit...S_Meter-HM_Digital_Inc.-RO1312-FIROPM-vi.html

 

[Denbf58]

just look at it this there is always room for improvement seeing you are doing fish only i would say you will be okay you can always add a DI unit for about $40. good luck and enjoy the hobby. [welcome]

 

[fishchef]

Thanks everybody for all the feedback. I tested again but this time I waited for the numbers to stabilize on my meter before getting a value. Tap reads 492 and RO 27. Based on the values (27 is 5.5% of 492 and filtration system is operating at 94.5% efficiency) my filter is ok right? It's kind of early to change the filters since its only like 7 months old. But come to think of it looking at the instruction manual for my meter the manufacturer claims it has already been professionally calibrated and no further calibration is necessary. I think I'll buy some distilled water when I get the chance and manually recalibrate to make sure. Or better yet the calibration fluid. Where can I get that?

Fluid can be found at BRS or any reef supply house. You should change the sediment and carbon block like every 6 months to protect and prolong the life of your membrane.

 

[mcgyvr]

Dear all,

Anyone using this TDS tester? All good reviews, no need to calibrate.

http://www.marinedepot.com/HM_Digit...S_Meter-HM_Digital_Inc.-RO1312-FIROPM-vi.html

Yep.. Works just fine..
Many of us have that as part of our RO/DI systems..
I put one probe on the inlet water and one after the DI stage..
The triple isn't a bad idea either as you can then have one also after the RO membrane to monitor its rejection rate..
http://www.bulkreefsupply.com/dual-inline-tds-meter-dm-1-hm-digital.html
http://www.bulkreefsupply.com/triple-inline-tds-meter-trm-1-hm-digital.html

 

[Tanthaitrung]

Yep.. Works just fine..
Many of us have that as part of our RO/DI systems..
I put one probe on the inlet water and one after the DI stage..
The triple isn't a bad idea either as you can then have one also after the RO membrane to monitor its rejection rate..
http://www.bulkreefsupply.com/dual-inline-tds-meter-dm-1-hm-digital.html
http://www.bulkreefsupply.com/triple-inline-tds-meter-trm-1-hm-digital.html

Thanks for your information :thumbsup:

No need to calibrate for the dual. But I don't know why the triple must be calibrated

 

[xREEFINaintEZx]

Thanks everybody for all the feedback. I tested again but this time I waited for the numbers to stabilize on my meter before getting a value. Tap reads 492 and RO 27. Based on the values (27 is 5.5% of 492 and filtration system is operating at 94.5% efficiency) my filter is ok right? It's kind of early to change the filters since its only like 7 months old. But come to think of it looking at the instruction manual for my meter the manufacturer claims it has already been professionally calibrated and no further calibration is necessary. I think I'll buy some distilled water when I get the chance and manually recalibrate to make sure. Or better yet the calibration fluid. Where can I get that?

Amazon... https://www.amazon.com/gp/aw/d/B001VE99X8/ref=mp_s_a_1_1?ie=UTF8&qid=1473177733&sr=8-1&pi=SY200_QL40&keywords=tds+calibration+solution&dpPl=1&dpID=41Q43Q12WvL&ref=plSrch. They have 2 kinds... I believe the NiCl is what I want