RO/DI unit test !!!!

[Civicdemon]

OK so i finally got my tds metter from amazon. after taking a readding of my tap water at 175 ppm i said wow. So i then went to the Container i have for Top off water and read that water and it was at 35 ppm, this still sounds high to me so i went to my RO/DI unit and made some freesh water, i tested it and it read 5 ppm, My question is will the top offwater in a countainer get worst as it sits ???? If so is this watter still good to use as top off water or even to mix my salt with ??? what are good ppm reading to use for making salt water ???

 

[MikeG]

The water coming out of your RO/DI unit should be 0 ppm. Are your filters old?? The water going into my RO/DI is between 45-47 ppm and coming out is 0 ppm.

 

[Civicdemon]

No all my filter are brand new just placed them in about 1 week ago, i have only made maybe 40 gl of water out of it so far. And also had it breaking in for about 1 1/2 hours before keeping water. Maybe its not fully broken in yet
.

 

[bjohanson1234]

The biggest question is if you calibrated your TDS meter? If not, then your readings aren't accurate.

 

[Civicdemon]

Dont they come Pre calibrated ???

 

[MikeG]

They usually do, but it could be off.

 

[Civicdemon]

So at 5 ppm im i safe to use the water for my water changes, im thinking i might have used the water to soon and might have had to wait for it to break in a bit more thats why i got a bit of a diatom / green film algea on my sand bed.

 

[Civicdemon]

Is there anywhere i can get calibration solution, or only order it online ?

 

[bjohanson1234]

When I got mine, the water in was reading 140-150. I calibrated it and the water in is now reading 110-120. The output always read 0. So calibrating your TDS could very well bring your readings into range. Also, depending on various factors such as rejection rate of your RO membrane and types of contaminants in your water, you might never get all the way down to 0. Many people recommend that less that 10 is adequate.

 

[bjohanson1234]

Is there anywhere i can get calibration solution, or only order it online ?

I peered mine when I got my unit. You LFS might have some.

 

[Civicdemon]

OK ill look into getting some solution. If no one has it i will order from amazon. But for the mean time if its comming out at under 10 ppm i should be good right ???

Also why would it read 5 now but when i tested the water made on sunday yesterday. 3 days later that water read 35 ppm, could that be because it had not fully broken in yet ??

 

[Bifferwine]

You can get calibration solution from Ebay for $3 or $4. TDS of 5 is fine to use. In some places, it just might not be possible to get it down to zero if the tap water is really bad (in Tucson, the TDS of my tap water is 400 to 500 -- I have NEVER been able to get my TDS down to zero when it starts off that high).

What did you have in the container before you put the water in there? If you have used it for anything else but RODI water, then it will have some residue on it which can raise the TDS. Like if you have used it for saltwater for water changes.

 

[Civicdemon]

Yes actually i use it for my water changes. I pump the water from my trash can into those 5to gl countainers then pore into the tank since i dont ha e a pump steon enog to bring the water from the garage to my dt about 40 feet away.

 

[Bifferwine]

If you use it for water changes, then there is going to be some salt on the inside of the container from the saltwater that was previously in it. That is why the TDS went up when you moved the RODI water into that container. This isn't a problem -- you can use the same container for both types of water. The salt residue left on the walls of the container is so minimal that it's not going to impact anything.

 

[Civicdemon]

Oh ok cool ao right now i messured my good watter and bad qater for one minute. The good water was at 1cup and the bad was a little over 3 cups almost at 3 1/4. I think that might not be good waste ratio it should be closer to 4me times right. Should i cut down.the flow restrictor more it only has about 2 inches in length left.

 

[Bifferwine]

No, if you are producing less waste and the TDS of the water coming out is good, then there's no reason to adjust it so that it's producing more waste.