Sky hight No3

Water Dog · Nov 16, 2018

Did you mean to say you can’t get below 8 TDS?

If so, this seems like it could be the underlying problem with your high nitrates. What RO membrane are you using (GPD) and how old is it? Do you know what your incoming TDS is?

Mr-TorchCoral · Nov 16, 2018

Water Dog said:
Did you mean to say you can’t get below 8 TDS?

If so, this seems like it could be the underlying problem with your high nitrates. What RO membrane are you using (GPD) and how old is it? Do you know what your incoming TDS is?

8 is the lower i ever got and i have an 3 stage RODI machine i dont really know where i got it from again.

Water Dog · Nov 16, 2018

Without specifics, it’ll be difficult to diagnose what your issues are.

If you could find out what RO membrane you’re using... 50, 75, 90 or 100 gpd as well as your TDS reading straight from the faucet, that will help figure out why you can’t get lower than 8 TDS from the unit.

Mr-TorchCoral · Nov 16, 2018

Water Dog said:
Without specifics, it’ll be difficult to diagnose what your issues are.

If you could find out what RO membrane you’re using... 50, 75, 90 or 100 gpd as well as your TDS reading straight from the faucet, that will help figure out why you can’t get lower than 8 TDS from the unit.

i use 50 i believe

Water Dog · Nov 16, 2018

Is one of the filters a DI stage? Or are you running 1 sediment filter and 2 carbon blocks?

Mr-TorchCoral · Nov 16, 2018

Water Dog said:
Is one of the filters a DI stage? Or are you running 1 sediment filter and 2 carbon blocks?

ill have to take a look at that but im not home now so.. i wil report it as quick as possible

Water Dog · Nov 16, 2018

My point in asking questions is this...

A top of the line Dow Filmtec 50 GPD membrane has a 98% rejection rate. If you’re not running a DI stage and everything is running optimally, then your incoming TDS must be at 400 if your product water is 8.

That’s why I’m asking if you know what your incoming TDS from the faucet is. If it’s lower than 400, then there may be a problem with your membrane or unit.

Furthermore, if you’re also running a DI stage and getting 8 TDS, then we have more problems that we need to troubleshoot for.

lakai · Nov 22, 2018

likely doesn't have a di stage or the di resin is completely spent.. If he's getting 8 tds then the membrane is likely working because sediment and carbon blocks alone wouldn't bring it down to that level. gl

Water Dog · Nov 22, 2018

lakai said:
likely doesn't have a di stage or the di resin is completely spent.. If he's getting 8 tds then the membrane is likely working because sediment and carbon blocks alone wouldn't bring it down to that level. gl

I’m guessing the OP has one of those “buddy” type RO units. But that’s why I’m asking a myriad of questions to ultimately get to the source of the high nitrate issues that is plaguing the OP. Based on what we know so far, it looks as though the water used to make new saltwater may potentially be the culprit.

Frtdrmrose7 · Nov 22, 2018

Mr-TorchCoral said:
i have an rodi unit with 3 stages and bought new filters 1 month ago. but i can get below 8 tds

You cannot get below 8 TDS? Are you on well water? In a city? Did you replace the R/O membrane also a month ago? If so did you flush 30-45 gallons through it before making water for your tank?

Mr-TorchCoral · Nov 23, 2018

Frtdrmrose7 said:
You cannot get below 8 TDS? Are you on well water? In a city? Did you replace the R/O membrane also a month ago? If so did you flush 30-45 gallons through it before making water for your tank?

i replace every compartmend and no i did not l=flush it...
are you supposed to do that? XD

Mr-TorchCoral · Nov 23, 2018

Water Dog said:
I’m guessing the OP has one of those “buddy” type RO units. But that’s why I’m asking a myriad of questions to ultimately get to the source of the high nitrate issues that is plaguing the OP. Based on what we know so far, it looks as though the water used to make new saltwater may potentially be the culprit.

im using a osmopure 50 ba

Frtdrmrose7 · Nov 23, 2018

Mr-TorchCoral said:
i replace every compartmend and no i did not l=flush it...
are you supposed to do that? XD

Yes before the first use you should flush the membrane with 30-40 gallons of water. There is a preservative in the membrane that needs to be flushed out before use. This could be part of your problem.