TDS of rodi

[Garf]

your DI cannisters are in backwards. there's an arrow on the cannister for this way up.

Backwards won’t make any difference as long as they are full of water

 

[Garf]

Yes a pen

You need an in line , to be able to trouble shoot

 

[JKDMan]

You need an in line , to be able to trouble shoot

Can't get one for a while

 

[Garf]

Can't get one for a while

Ok, you can do it manually.
Disconnect pipe from RO, put it into a clean glass and test it with your pen.
Reconnect then;
Put pipe from DI into clean glass, test with pen.

 

[sp1187]

Backwards won’t make any difference as long as they are full of water

wrong.
then why is there an arrow on the cannister on how it goes in?
I did this. and so have others reported this issue and I told them the DI was in upside down. funny thing.... when they put it in correctly the TDS went to zero.

 

[Garf]

wrong.
then why is there an arrow on the cannister on how it goes in?
I did this. and so have others reported this issue and I told them the DI was in upside down. funny thing.... when they put it in correctly the TDS went to zero.

The resin is in water, it makes little difference if it’s going forwards or backwards.

 

[sp1187]

The resin is in water, it makes little difference if it’s going forwards or backwards.

then why do the cannisters, at least in the system I have (BRS) specifically show which way the DI cannister has to be placed? and why when it's backwards does the in line meter and a hand held meter show TDS but when it's in as it's supposed to be the meters read zero?

 

[Garf]

then why do the cannisters, at least in the system I have (BRS) specifically show which way the DI cannister has to be placed? and why when it's backwards does the in line meter and a hand held meter show TDS but when it's in as it's supposed to be the meters read zero?

Ok, chill. I’ve made 12000 ltrs per day of DI at work for the last 30 years from tap water, no RO. I regen my own DI. Channelling is an issue in DI systems.

 

[Biglew11]

Backwards is not upside down. The cartridge will only go in one way. Other poster thought you were talking about flow through the whole canister. This direction wont matter.

 

[sp1187]

Ok, chill. I’ve made 12000 ltrs per day of DI at work for the last 30 years from tap water, no RO. I regen my own DI. Channelling is an issue in DI systems.

not being argumentative. just saying when I had them in upside down, and others I've talked to the same, it made a difference. very minor difference, but wouldn't zero out until the cannister was flipped.
apologies to the OP.

 

[JKDMan]

wrong.
then why is there an arrow on the cannister on how it goes in?
I did this. and so have others reported this issue and I told them the DI was in upside down. funny thing.... when they put it in correctly the TDS went to zero.

Almost 100% sure it's oriented correctly but I'll check

 

[JKDMan]

Backwards is not upside down. The cartridge will only go in one way. Other poster thought you were talking about flow through the whole canister. This direction wont matter.

What's difference ... how do you put a cylinder on backwards?

 

[Garf]

Red herring, the problem is elsewhere

 

[JKDMan]

Red herring, the problem is elsewhere

Such as?... also no one has commented on the container... could it be not visibly dirty but contributing to the reading?

 

[JKDMan]

Such as?... also no one has commented on the container... could it be not visibly dirty but contributing to the reading?

Also how do I calibrate the meter? Just thought it about it but maybe that's the issue

 

[Garf]

Yes it could. But you need to test before the container to work that one out.

 

[JKDMan]

Yes it could. But you need to test before the container to work that one out.

Ya I'm going to tonight

 

[Uncle99]

The resin is in water, it makes little difference if it’s going forwards or backwards.

filling and pushing water up through the resin is the most appropriate as the water will not channel which lowers contact time. Filling from the top downwards is not the best approach, but will work.

 

[robbyg]

Without TDS numbers for incoming water and after the Ro Membrane this is going to be impossible to trouble shoot.

I have had this issue before when it was 290 at the Input and about 15 at the Ro output and then after Di it was 35. I have also had it be 15 at the Ro output and 18 at the Di Output.

In the case of the 35 it was due to bad Di resin. I got a new batch that was sealed properly on arrival and the TDS dropped instantly to Zero.

In the Case of 18 it was because the washer at the top of the Ro canister was so worn out that it allowed water to pass right around it. A new washer solved the problem.

I can save you some time and tell you that running a whole bunch of water through the system will not make things better. When i had 35ppm I tried running about 10 gallons and that did almost nothing.
The minute I put in new Di resin and ran about half a gallon through it the TDS was Zero.

 

[robbyg]

Ah, then the obvious answer could be you have really crappy water.
You may need to add additional DI canister to get down to 0.

I don't agree with this. If the water was even at 200 tds the Di resin would drop it to zero. The only problem would be that you would go through a canister of Di resin every couple of days.